This one:

The UK Home Office hostile environment policy is a set of administrative and legislative measures designed to make staying in the United Kingdom as difficult as possible for people without leave to remain, in the hope that they may "voluntarily leave".[1][2][3][4][5] The Home Office policy was first announced in 2012 under the Conservative-Liberal Democrat coalition.[6] The policy was widely seen as being part of a strategy of reducing UK immigration figures to the levels promised in the 2010 Conservative Party Election Manifesto.[7][8][9]

The policy has been cited as one of the harshest immigration policies in the history of the United Kingdom, and has been widely criticised as inhumane, ineffective, and unlawful.[10][11] The United Nations Human Rights Council has stated that the policy has fostered xenophobia within the UK, while the Equality and Human Rights Commission has found that the policy broke equalities law.[12][13]

It has notably led to significant issues with the Windrush generation and other Commonwealth citizens being deported after not being able to prove their right to remain in the UK, despite being guaranteed that right.[14] The resulting Windrush scandal led to the resignation of Amber Rudd as Home Secretary, on 29 April 2018, and the appointment of Sajid Javid as her successor.[15][16][17]

https://en.wikipedia.org/wiki/Home_Office_hostile_environmen...

The issue of immigration has been a controversial political issue since the late 1990s. Both the Labour Party and the Conservatives have suggested policies perceived as being "tough on asylum"[88] (although the Conservatives have dropped a previous pledge to limit the number of people who could claim asylum in the UK, which would likely have breached the UN Refugee Convention)[89] and the tabloid media frequently print headlines about an "immigration crisis".[90]

This is denounced, by those seeking to ensure that the UK upholds its international obligations, as disproportionate. Concern is also raised about the treatment of those held in detention and the practice of dawn raiding families, and holding young children in immigration detention centres for long periods of time.[91][92] The policy of detaining asylum-seeking children was to be abandoned as part of the coalition agreement between the Conservatives and the Liberal Democrats, who formed a government in May 2010.[93] However, in July 2010 the government was accused of back-tracking on this promise after the Immigration Minister Damian Green announced that the plan was to minimise, rather than end, child detention.[94]

https://en.wikipedia.org/wiki/Modern_immigration_to_the_Unit...

In May 2018 under the tenure of Sajid Javid, it was the view of a significant minority that the Home Office was misusing section 322(5) of the Immigration Rules.[66][67] The section was designed to combat terrorism, but the Home Office had been wrongly applying it to hundreds of settled, highly skilled workers.[66][68][69][70] The hardship faced by the workers was compared to the Windrush scandal, which occurred around the same time.[66][71][72][70] By early 2019, approximately 90 people had been deported from the UK due to section 322(5).[73]

https://en.wikipedia.org/wiki/Modern_immigration_to_the_Unit...

In September 2020 Patel asked officials to look at asylum policies which had been successful in other countries. It was suggested that Ascension Island, more than 4,000 miles (6,400 km) from the UK, could be used to build an asylum processing centre. Labour's shadow home secretary Nick Thomas-Symonds said: "This ludicrous idea is inhumane, completely impractical and wildly expensive - so it seems entirely plausible this Tory government came up with it."[88]

In March 2021, Patel published a New Plan for Immigration Policy Statement, which included proposals to reform the immigration system, including the possibility of offshore processing of undocumented immigrants.[89] In April 2021, 192 refugee, human rights, legal and faith groups signed a letter which condemned a six-week consultation, organised by the Home Office, on these proposals. Signatories of the letter described the consultation as "vague, unworkable, cruel and potentially unlawful".[90][91]

In May 2021, a high court judge criticised Patel in court and said he found it "extremely troubling" that one of her officials admitted the Home Office may have acted unlawfully in changing its asylum accommodation policy during the COVID-19 pandemic. Following the judge's comments, a solicitor representing Patel apologised on her behalf.[92]

In June 2021, a High Court judge ruled that the Home Office acted unlawfully by housing asylum seekers in an "unsafe" and "squalid" former army barracks. The judge found that the Home Office failed to look after vulnerable people and noted that a lack of safety measures had contributed to a "significant" risk of injury and death from fires or from coronavirus.[93][94]

https://en.wikipedia.org/wiki/Priti_Patel#Asylum_seekers