Dominic Grieve and Phillip Lee were greeted with cheering and applause by anti-Government protesters as they spoke at a cross party rally outside Parliament.
Hundreds of people filled Parliament Square on Wednesday evening for the Defend Our Democracy rally, which featured talks from Labour, Green Party and Liberal Democrat MPs.
But it was former Conservative Mr Grieve who received some of the biggest cheers as he went on stage to chants of Oh, Dominic Grieve, a chant usually reserved for Labour leader Jeremy Corbyn.
Addressing the crowd, he said: “It fills me with horror to see a Conservative government behaving more like a revolutionary junta, threatening to disregard every democratic norm.
“If they decide to get rid of me, then I am quite pleased.”
At times, the cheers turned to chants of “Johnson out” as speakers took turns to criticise the Prime Minister and the prospect of a no-deal Brexit.
Meanwhile a small contingent of Brexit supporters heckled Labour MPs shouting “Leave means Leave” and “left wing coup” as they walked away from Parliament Square.
Protesters waved blue EU flags and placards calling for a people’s vote during the evening.
Retired secondary school headteacher Ashley Pellegrini, 70, said he travelled up from Dorset in “defence of democracy”.
He said: “I am absolutely appalled that 21 Conservative MPs who have been loyal to their party and country have had the whip withdrawn.
The Labour-turned-Liberal Democrat supporter said: “I feel democracy is dying within the country.”
Meanwhile, London tourist guide Kate Palmer, 74, said she was unsure as to whether she would like to see another election.
“I am not sure another election will change anything at the moment, especially with the unpopularity of the leader of the Labour Party,” Ms Palmer, of Tulse Hill, south London, said.
“Because of our awful voting system it would solve anything, it might make things worse.”
Green Party co-leader Caroline Lucas and Liberal Democrat leader Jo Swinson were among the rally’s speakers.
Ms Lucas said: “If they try to close down Parliament we will set up another one.
“If they try to close down the House of Commons, we will close down the streets.”
Across the road from Parliament Square was a small contingent of Brexit supporters, who stood by placards reading Leave Means Leave.
Robert Harwood, 57, of west London, said: “I do support a no-deal Brexit because we will get our sovereignty back.
“I don’t think Brexiteers are worried about the economic cost. It is about sovereignty.”
Richard Fullerton, a 53-year-old marketing consultant from Newmarket and a Ukip member, said: “This is all about the Conservative Party readjusting to what it was.
“The reason it has moved right is because it has been moved left for the past 20 years.
“I do support early elections.”
Teaching assistant Will Coleshill, 24, from North London, said: “I think MPs should vote for us to leave the EU and restore democracy.
“It is disgusting elected representatives would undermine the interests of the nation.”
Mr Lee crossed the floor of the Commons to join the Liberal Democrats while Mr Grieve lost the Tory whip after voting against the Government.
Police led away two men after a brief clash broke out with protesters from the Labour Campaign for Free Movement.
Dozens of people waving flags and holding flares moved onto Parliament Square in London following the conclusion of the Defend Our Democracy rally on Wednesday evening.
But an argument broke out when two men, one of whom was carrying a Ukip flag, engaged with members of the crowd.
It led to the protesters chanting “Nazi scum, off our streets”, before a brief scuffle occurred involving two other men nearby.
Both men were led away from Parliament Square by officers.