Leader of the Catholic People's Party Carl Romme, Leader of the Anti-Revolutionary Party Jelle Zijlstra, Prime Minister and Leader of the Labour Party Willem Drees, Leader of the People's Party for Freedom and Democracy Pieter Oud, Deputy Leader of the Labour Party Jaap Burger and Leader of the Christian Historical Union Hendrik Tilanus during a meeting at the Ministry of General Affairs on 20 June 1956.