Opinion of the Advocate General — ECLI:EU:C:2024:475
Date: 2024-06-06
Language of the case: Spanish
Procedure: Reference for a preliminary ruling
Origin: Spain

Summary C-314/23 – 1 
Case C-314/23 
Summary of the request for a preliminary ruling pursuant to Article 98(1) of 
the Rules of Procedure of the Court of Justice 
Date lodged: 
22 May 2023 
Referring court: 
Audiencia Nacional (Spain) 
Date of the decision to refer: 
17 March 2023 
Applicant: 
Sindicato de Tripulantes Auxiliares de Vuelo de Líneas Aéreas 
(STAVLA) 
Defendants: 
Air Nostrum, Líneas Aéreas del Mediterráneo, S. A. 
Federación de Servicios de Comisiones Obreras (CCOO) 
Unión General de Trabajadores (UGT) 
Unión Sindical Obrera (USO) 
Comité de empresa de Air Nostrum Líneas Aéreas del 
Mediterráneo, S. A. 
Dirección General de Trabajo 
Instituto de las Mujeres 
Dirección General de Igualdad de la Comunidad de Madrid 
Ministerio Fiscal 
  
EN 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-314/23 
 
2  
Subject matter of the main proceedings 
Challenge to a collective agreement – Cabin crew – Provision regulating the daily 
subsistence allowance – Indirect discrimination on grounds of sex compared to 
pilots 
Subject matter and legal basis of the request 
Article 267 TFEU – Request for a preliminary ruling on interpretation – Directive 
2006/54/EC – Indirect discrimination on grounds of sex 
Question referred for a preliminary ruling 
Does the fact that the company AIR NOSTRUM compensates a group such as 
cabin crew, where the majority of the individuals making up the group are 
women, for the expenses which they have to meet when travelling, other than 
those related to transport and accommodation, with an amount smaller than that 
received for the same expenses by another group of employees, such as pilots, in 
which the majority are men, constitute an instance of indirect discrimination on 
grounds of sex in relation to working conditions, contrary to European Union law 
and prohibited under Article 14(1)(c) of Directive 2006/54, where the reason for 
such different treatment lies in the fact that each group is subject to a different 
collective agreement, both negotiated by the same company but with different 
union representatives, pursuant to Article 87 of the Estatuto de los Trabajadores 
(Spanish Workers’ Statute; ‘the Workers’ Statute’)? 
Provisions of European Union law relied on 
Treaty on the Functioning of the European Union, Article 8. 
Charter of Fundamental Rights of the European Union, Articles 23 and 28. 
Directive 2006/54/EC of the European Parliament and of the Council of 5 July 
2006 on the implementation of the principle of equal opportunities and equal 
treatment of men and women in matters of employment and occupation, 
Articles 2(1)(b) and 14(1)(c). 
Provisions of national law relied on 
1. Spanish Constitution 
Article 14: ‘Spanish people are equal before the law; there may be no 
discrimination on grounds of birth, race, sex, religion, opinion or any other 
condition or personal or social circumstance.’ 
STAVLA 
 
3 
Article 37(1): ‘The law shall guarantee the right to collective bargaining 
between workers’ representatives and employers, as well as the binding 
force of the agreements.’ 
2. Ley Orgánica 3/2007, de 22 de marzo, para la igualdad efectiva de mujeres y 
hombres (Organic Law 3/2007, of 22 March 2007 on effective equality 
between women and men). 
Article 5: ‘Equal treatment and opportunities as regards access to 
employment, vocational training and promotion and working conditions. 
The principle of equal treatment and opportunities for men and women, 
applicable to private-sector and public-sector employment, shall, in 
accordance with the applicable regulations, be guaranteed as regards access 
to employment, including self-employment, vocational training, career 
advancement, working conditions, including pay and dismissal, and 
membership of and involvement in trade unions and employers' 
organisations, or any organisation whose members carry on a particular 
profession, including the benefits granted by such organisations. 
A difference of treatment which is based on a characteristic related to sex 
shall not constitute discrimination as regards access to employment, 
including the necessary training, where, by reason of the nature of the 
particular occupational activities concerned, or of the context in which they 
are carried out, such a characteristic constitutes a genuine and determining 
occupational requirement, provided that the objective is legitimate and the 
requirement is proportionate.’ 
Article 6(2): ‘Where an apparently neutral provision, criterion or practice 
puts persons of one sex at a particular disadvantage compared with persons 
of the other sex, unless that provision, criterion or practice is objectively 
justified by a legitimate aim, and the means of achieving that aim are 
necessary and appropriate, it is considered to be indirect discrimination on 
grounds of sex.’ 
3. Ley 15/2022, de 12 de julio, integral para la igualdad de trato y la no 
discriminación (Law 15/2022, of 12 July on equal treatment and non-
discrimination,). 
This law also contains, in essence, provisions relating to the prohibition of 
discrimination, inter alia, on grounds of sex. 
4. Real Decreto Legislativo 2/2015, de 23 de octubre, por el que se aprueba el 
texto refundido de la Ley del Estatuto de los Trabajadores (Royal 
Legislative Decree 2/2015, of 23 October 2015, approving the consolidated 
text of the Workers’ Statute). 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-314/23 
 
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Article 17(1), first subparagraph: ‘Any regulatory provisions, clauses of 
collective agreements, individual agreements and unilateral decisions of the 
employer which, as regards employment, remuneration, working hours or 
other working conditions, give rise to unfavourable situations of direct or 
indirect discrimination on grounds of age or disability, or to situations of 
direct or indirect discrimination on grounds of sex, origin, including racial or 
ethnic origin, marital status, social standing, religion or beliefs, political 
views, sexual orientation and identity, gender expression, sexual 
characteristics, membership or otherwise of trade unions and participation or 
otherwise in their agreements, family ties with individuals belonging to or 
connected with the company, or language, within the Spanish state, shall be 
regarded as void and without effect.’ 
Article 26(2): ‘Sums received by a worker by way of compensation or 
allowances for expenses incurred as a consequence of his or her work, social 
security benefits and allowances and compensation for relocation, 
suspension or dismissal shall not be regarded as salary.’ 
Article 87(1), fourth subparagraph: ‘In agreements aimed at a group of 
workers with a specific occupational profile, the trade union branches which 
have been designated by a majority of the individuals they represent by 
means of personal, free, direct and secret ballot, shall have the authority to 
negotiate.’ 
5. IV Convenio Colectivo de Air Nostrum, Líneas Aéreas del Mediterráneo, 
S. A., (personal de tierra y TCP´S) (4th Collective Agreement of Air 
Nostrum, Líneas Aéreas del Mediterráneo, S. A., (ground staff and cabin 
crew); ‘the Collective Agreement for Ground Staff and Cabin Crew’), which 
was published in the Boletín Oficial del Estado (Official State Gazette) on 
14 January 2019 and was signed by the company’s management, on the one 
hand, and by the trade unions Unión General de Trabajadores (General 
Workers’ Union; ‘the UGT’), Federación de Servicios de Comisiones 
Obreras (Workers’ Commissions Services Federation; ‘the CCOO’) and 
Unión Sindical Obrera (Workers’ Syndical Union; ‘the USO’), on the other. 
In that agreement, the daily subsistence allowance is defined as the amount 
which compensates members of cabin crew for expenses, other than those 
related to transport and accommodation, occasioned by travel forming an 
integral part of the content of the services they provide. 
Cabin crew are entitled to half of the daily subsistence allowance if they 
provide their services for four hours or less and the full daily subsistence 
allowance if they provide their services for more than four full hours. The 
amounts of the daily subsistence allowance appear in Annex I to that 
collective agreement: 
‘ANNEX I 
STAVLA 
 
5 
Cabin crew salary tables 
Professional group IV: Cabin crew 
1 Tier 1 Tier 2 Tier 3 Tier 4 Tier 5 
National with 
overnight 
39.37 39.37 39.37 39.37 39.37 
National no 
overnight 
37.06 37.06 37.06 37.06 37.06 
International 
with overnight 
59.06 59.06 59.06 59.06 59.06 
International no 
overnight 
56.74 56.74 56.74 56.74 56.72’ 
6. Convenio Colectivo de Air Nostrum LAM, S.A., (Pilotos) (Collective 
Agreement of Air Nostrum LAM, S. A., (Pilots); ‘the Collective Agreement 
for Pilots’), which was published in the Boletín Oficial del Estado (Official 
State Gazette) on 13 May 2020 and was signed by the company’s 
management, on the one hand, and the branches of the trade unions 
Sindicato Español de Pilotos de Líneas Aéreas (Spanish Airline Pilots’ 
Union; ‘SEPLA’) and Unión Profesional de Pilotos de Aerolíneas 
(Professional Airline Pilots’ Union; ‘the UPPA’), on the other. 
That collective agreement defines the daily subsistence allowance as the 
amount payable to the pilot, in order to meet expenses, other than 
accommodation and transport, arising from travel undertaken for the needs 
of the company or from staying away from his or her base. 
The agreement provides that the pilot is entitled to the daily subsistence 
allowance on flight days. It also states that if, after five days of service, the 
pilot is away from his or her base, he or she is entitled to double the daily 
subsistence allows from the sixth day, inclusive. The amount of the daily 
subsistence allowance appears in Annex A: 
 ‘ANNEX A 
Period Payments Amount 
 Annual   
National 
Allowance day Variable €65.00 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-314/23 
 
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International 
Allowance 
 
day 
 
Variable 
 
€100.00’ 
Succinct presentation of the facts and procedure in the main proceedings 
1 On 14 January 2019, the Collective Agreement for Ground Staff and Cabin Crew 
was published in the Boletín Oficial del Estado (Official State Gazette). 
2 On 8 November 2022, the Sindicato de Tripulantes Auxiliares de Vuelo de Líneas 
Aéreas (Airline Flight Attendants’ Union: ‘STAVLA’) brought a claim in the 
Audiencia Nacional (National High Court, Madrid) seeking to have the amounts 
of the daily subsistence allowance appearing in that collective agreement declared 
invalid. According to STAVLA, cabin crew (the vast majority of whom are 
women) as a group suffer indirect discrimination on grounds of sex compared to 
pilots (the vast majority of whom are men) as a group. 
3 Being unsure how to resolve the dispute, the National High Court decided to 
submit this request for a preliminary ruling. 
The essential arguments of the parties in the main proceedings 
4 According to STAVLA, cabin crew (94% of whom are women) as a group suffer 
indirect discrimination on grounds of sex compared to pilots (93.71% of whom 
are men) as a group with regard to the daily subsistence allowance. STAVLA 
notes that, according to Spanish employment legislation, the daily subsistence 
allowance does not constitute salary, but rather compensation paid on account of 
having to incur expenses while travelling, such as eating daily meals away from 
the usual place of residence. That implies that, for the purposes of comparison, the 
higher or lower value of the work done cannot be taken into consideration as a 
justification for the difference. 
5 The Ministerio Fiscal (Public Prosecutor’s Office) agrees with STAVLA. It also 
notes that the judgment of the Court of Justice of 8 September 2011, Hennigs and 
Mai (C-297/10 and C-298/10, EU:C:2011:560), which held that the exercise of 
collective bargaining does not justify discriminatory treatment, is applicable to the 
present case. 
6 Air Nostrum and the trade union SEPLA (which negotiated the collective 
agreement for pilots) contest the claim. First, they dispute the notion that the 
groups are comparable, as they do not do work of equal value, which justifies 
different treatment as regards remuneration. Second, they maintain that the 
difference in treatment is, in any case, justified by the legitimate exercise of the 
right to collective bargaining, since, given that national legislation authorises what 
is known as a ‘convenio colectivo de franja’ (literally, a ‘band’ collective 
STAVLA 
 
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agreement; a collective agreement solely applicable to workers having a specific 
professional profile, such as pilots), it is a logical consequence of the fact that two 
negotiation processes are carried out separately that the working and employment 
conditions applicable to the different groups of workers are different. 
Consequently, they assert that STAVLA is proposing the partial application of a 
collective agreement to a group that is not included in its scope. 
7 The Abogacía del Estado (Legal Service of the Spanish Government) supports this 
argument. 
Succinct presentation of the reasoning in the request for a preliminary ruling 
8 First, within Air Nostrum, a group mostly made up of women receives, as 
compensation for the expenses which they have to meet when travelling, other 
than those related to transport and accommodation, a smaller amount than that 
received by another group of employees, mostly made up of men, for the same 
expenses. 
9 In order for the different treatment described not to constitute indirect 
discrimination on grounds of sex, Air Nostrum would have to show that it serves a 
legitimate aim and that the means of achieving that aim are appropriate and 
necessary. 
10 The amounts which Air Nostrum pays both to cabin crew and to pilots are not 
regarded as salary, either from the perspective of Spanish employment legislation, 
as they are expressly excluded from that concept by Article 26(2) of the Workers’ 
Statute, or from the point of view of EU law (Article 157 TFEU and 
Article 2(1)(e) of Directive 2006/54/EC). That is because those amounts are not 
paid for specific work calculated by unit of time or unit of work, which implies 
that the different value of the work done by pilots and by cabin crew cannot be a 
factor that justifies such different treatment. 
11 The origin of the different treatment lies in the fact that the working conditions of 
each of the two groups are governed by specific collective agreements, which 
were negotiated by the same company but with different union representatives, in 
conformity with Spanish legislation. 
12 There could be no doubting the existence of indirect discrimination on grounds of 
sex if the different compensation for each of the two groups as regards the daily 
subsistence allowance had been established in the same collective agreement. The 
uncertainty arises because the origin of the different treatment lies in the fact that, 
within the company, two different collective agreements, negotiated with different 
union representatives, are applied. Furthermore, it must be supposed that, in each 
collective bargaining negotiation with the company, the union representatives 
concerned prioritised certain demands over others and that each agreement is the 
product of a different negotiation in which the representatives in question put 
certain demands ahead of others. 
SUMMARY OF THE REQUEST FOR A PRELIMINARY RULING – CASE C-314/23 
 
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13 Therefore, we do not consider the case-law expressed in the judgment of the Court 
of Justice of 8 September 2011, Hennigs and Mai (C-297/10 and C-298/10, 
EU:C:2011:560) to be applicable to the present case, as that judgment deals with a 
case of discrimination on grounds of age arising from the negotiation of a single 
collective agreement, unlike the situation in the present case. 
14 Lastly, we must point out one significant fact, namely that, when Air Nostrum 
negotiated the collective agreement for pilots, the agreement which is now being 
challenged had already been signed; that is, Air Nostrum was fully aware of the 
amounts which had been agreed for cabin crew as regards the daily subsistence 
allowance.