Shouts of "jail them!" rang out at the UK Conservative party conference, as talk turned to the lawmakers who voted against Prime Minister Boris Johnson's strategy on Brexit.

Leading eurosceptic Steve Baker said his former colleagues "acted against the national interest", sparking calls for criminal action from the crowd -- although he urged restraint.

The flash of hostility in an otherwise largely upbeat and disciplined annual conference in Manchester, northwest England, reveals how deep tensions are running in the governing party.

Johnson last month expelled 21 MPs for voting with opposition parties to stop him possibly leaving the European Union without a divorce deal on October 31.

Few of the rebels are at this week's party meeting, where ministers fill the main stage and the airways with promises to "Get Brexit done", and moderates are consigned to the fringes.

Former finance minister Philip Hammond said he was staying away as he no longer recognised a party of "ideological puritanism that brooks no dissent and is more and more strident in its tone."

'Party of Trump'

But in a small, packed meeting room away from the main venue Monday, three expelled former ministers defended their stance to a largely supportive crowd.

They repeated their warnings that leaving the EU, Britain's closest trading partner, at the end of this month without agreeing divorce terms first would be a disaster.

They say they are not trying to block Brexit but argue that as Conservatives, the party should be more cautious.

Former justice minister David Gauke said the Tories had become a "more confrontational, much more aggressive party".

"We are no longer the party of (wartime leader Winston) Churchill, we are more the party of (US President Donald) Trump," he said.

His comments sparked shouts of "no!" and "rubbish" from the audience, but there was also prolonged applause.

Foul traitor

Gauke appeared alongside former attorney general Dominic Grieve, who has led parliament's battles with the government since the 2016 referendum.

Grieve wants a fresh poll on Brexit, saying people are now more informed about the complexities -- and particularly the dangers of "no deal".

"In my mind being a party loyalist always means putting country before party when that is necessary," he said.

"And we are at the moment 30 days away from a possibly catastrophic event in our country's peacetime modern history."

Grieve has been subjected to abuse, and read out a new message on his phone to the meeting, which accused him of being a "foul traitor".

"This sort of atmosphere... is being currently, I'm sorry to say bluntly, encouraged by the leader of the Conservative party," he said, referring to Johnson.

'Like it or get off'

The law the rebels helped pass demands that Johnson seek to delay Brexit if he cannot agree a divorce deal by a Brussels summit later this month.

The prime minister has called it a "surrender act", saying it would allow the EU to decide Britain's fate -- and undermine the chances of getting a deal.

Former junior foreign minister Alistair Burt, who originally opposed Brexit, said he wanted a divorce agreement but said his party had become obsessed.

"I've lost the argument -- the party has decided it wants to leave the EU," he said.

"But I've seen that process become an obsession to the point of irrationality, that really, really worries me."

Johnson has yet to show he can get a deal to allow Brexit on October 31, or how he can get around the law requiring him to delay if he fails.

But opinion polls indicate his tough talk is winning over pro-Brexit voters.

Linda Topping, 63, a local party chairwoman from Watford, north of London, said Conservatives should accept they must adapt with the times.

"We are supposed to be representing the voters and the voters are changing," she told AFP.

"If you don't like it, get off."