At the 2nd Congress of the RSDLP, which was held in Brussels and then London during August 1903, Lenin and Julius Martov disagreed over the party membership rules. Lenin, who was supported by Georgy Plekhanov, wanted to limit membership to those who supported the party full-time and worked in complete obedience to the elected party leadership. Martov wanted to extend membership to anyone "who recognises the Party Programme and supports it by material means and by regular personal assistance under the direction of one of the party’s organisations." Lenin believed his plan would develop a core group of professional revolutionaries who would devote their full-time and energy towards developing the party into an organization capable of leading a successful proletarian revolution against the Tsarist autocracy.