Britain cannot be bullied, Brexit minister Dominic Raab said on Monday, sharpening the government's criticism of the EU for taunting Prime Minister Theresa May and souring difficult Brexit talks.

May's ministers have come out one by one at their party's annual conference in the city of Birmingham to warn the EU that they will embrace leaving without a deal if the bloc fails to show "respect" in the talks to end Britain's membership.

Just six months before Britain is due to leave the EU in the country's biggest shift in foreign and trade policy in more than 40 years, May faces growing criticism over her proposals not only in her governing party but also in Brussels.

Party unity is on British ministers' minds, and they are encouraging the faithful to direct their anger at the EU rather than at their prime minister, who some euro-skeptic Conservatives accuse of leading Britain towards a "Brexit in name only".

But the new strident tone has annoyed many in Brussels, especially when foreign minister Jeremy Hunt compared the bloc to the Soviet Union, the master of several states in eastern Europe which saw membership of the EU as a measure of their freedom.

Other ministers, such as finance minister Philip Hammond, have taken a softer tone, pointing out that leaving without a deal could hurt Britain's economy, the world's fifth largest.

But Raab said he had called on the EU to match the "ambition and pragmatism" Britain had put forward with May's Chequers proposals, named after her country residence where an agreement with her ministers was hashed out in July.

"Unfortunately, that wasn't on display in Salzburg," he said, describing a summit last month in the Austrian city where EU leaders rejected parts of the Chequers plan.

"Our prime minister has been constructive and respectful. In return, we heard jibes from senior leaders and we saw a starkly one-sided approach to negotiation."

"What is unthinkable is that this government, or any British government, could be bullied by the threat of some kind of economic embargo, into signing a one-sided deal against our country's interests," Raab said, later calling again on the EU to move their position and meet Britain half way.

Instead of the much-hoped-for staging post, the Salzburg summit has become a byword for a sharp deterioration in the atmosphere of the talks, when British government officials felt May was ambushed by the other EU leaders over Brexit.

'No cherries'

With no divorce deal and a standoff over the shape of any future relationship, the possibility of a "no deal Brexit" has increased, with some businesses preparing for what they see as a worst-case scenario.

European Commission President Jean-Claude Juncker said the discussion in Britain over Brexit was still far removed from reality.

"The world is watching," said Matthew Fell, chief UK policy director at the Confederation of British Industry.

"Every signal is hugely important in terms of setting the tone. So the more that people can coalesce around some areas of agreement such as an industrial strategy, innovation and skills would be hugely helpful," he said.

But one source close to the government said there was now a sense that the EU had realized that the tone set in Salzburg was "perhaps a bit off" and, behind the scenes, conversations between the two sides were more constructive.

Raab later said the government was open to looking at regulatory checks to try to ease talks on a so-called backstop to prevent a return to a hard border between the British province of Northern Ireland and EU member Ireland - one of the outstanding issues yet to be agreed.

Hammond, for one, was keen to pursue a more positive stance.

After Brexit, Britain and the EU will still "be neighbors and we are going to have to carry on living with each other," he told the conference, again backing May's Chequers plan.

"Mr. Tusk says it won't work. But that's what people said about the light bulb in 1878. Our job is to prove him wrong."

But Hunt's popular line at conference, that the EU was acting like the Soviet Union, did little to soothe relations, provoking those eastern members of the bloc which only regained full independence after the collapse of the Soviet Union in 1991. They joined the EU more than a decade later.

Lithuania's EU commissioner Vytenis Andriukaitis told Hunt he was born in a Soviet gulag forced labor camp and was jailed by the Soviet KGB state security agency.

"Happy to brief you on the main differences between EU and Soviet Union," he said. "Anytime. Whatever helps."

But back in Birmingham, it was Raab, winning a standing ovation for his story about his father's journey from then Czechoslovakia after the Nazi invasion, who summed up Britain's new combative stance.

"The EU's theological approach allows no room for serious compromise," he said. "If the EU want a deal, they need to get serious."