Prime Minister Boris Johnson on Sunday declared Britain would break out of the European Union just like the comic book hero "The Incredible Hulk" and hailed "huge" progress towards getting a divorce deal.
The Conservative leader made the comments ahead of meetings with European Commission chief Jean-Claude Juncker and EU negotiator Michel Barnier in Luxembourg on Monday.
Johnson told the Mail on Sunday newspaper he was "very confident" of getting a divorce deal at an EU summit on October 17, in time for Brexit on October 31.
But his optimism is not universally shared, and a senior EU diplomat told AFP there was "nothing tangible so far" in terms of progress.
In an odd analogy, Johnson compared Britain to the Marvel Comics character Hulk -- the destructive alter ego of scientist Bruce Banner who turns into the ferocious green giant when enraged or stressed.
"The madder Hulk gets, the stronger Hulk gets and he always escaped, no matter how tightly bound in he seemed to be -- and that is the case for this country," he said.
But Johnson is facing strong opposition in parliament to his threat to leave the EU without a deal on October 31 if his negotiations fail.
Many of the rebels are on his own side and on Saturday night, one of his Conservative MPs defected to the pro-European Liberal Democrats.
Former universities minister Sam Gyimah, who briefly ran against Johnson for the party leadership this summer, condemned him for "veering towards populism".
The Lib Dems, who now have 18 MPs in the 650-seat House of Commons, on Sunday voted at their party conference to reverse Brexit if they ever won a majority in parliament.
Elsewhere, former prime minister David Cameron, who led the failed campaign to stay in the EU in 2016, accused Johnson in his memoirs of only pursuing Brexit out of political ambition.
The turmoil comes ahead of another crucial week, as the Supreme Court considers the legality of Johnson's decision to suspend parliament earlier this month until October 14.
- Hulk was a 'winner' -
Johnson was a leading "Leave" campaigner in the referendum, and took office in July promising to deliver Brexit no matter what.
He wants to renegotiate the terms struck by his predecessor Theresa May, which MPs have rejected, but EU leaders have so far refused.
Johnson repeated that "under no circumstances" would he delay Brexit.
He may have no choice after MPs last week passed a law to postpone Britain's exit date until January if he does not get a deal by the EU summit.
His comparison with Hulk drew derision from Guy Verhofstadt, Brexit coordinator for the European Parliament.
"Even to Trumpian standards the Hulk comparison is infantile. Is the EU supposed to be scared by this? The British public impressed?" he tweeted.
However, Brexit Secretary Steve Barclay told Sky News: "The Hulk was a winner and was extremely popular."
- Sticking points -
Johnson told the Mail there was a "very good conversation" going on about the key sticking point in the Brexit deal, the issue of the Irish border.
"A huge amount of progress is being made," he said.
However, a European source close to the negotiations repeated that Brussels had yet to receive "concrete proposals".
Much of the British opposition to the current terms is focused on the so-called backstop plan to keep open the Irish border.
It could keep Britain indefinitely tied to EU trade rules to avoid frontier checks between British Northern and EU member Ireland.
Barclay insisted "the backstop needs to go", while adding: "We can see a landing zone in terms of a future deal but there is significant work still to do."
- 'Truth-twisting populism' -
Twenty-one Conservatives rebelled to back the law to delay Brexit and were expelled from the party, leaving Johnson without a majority in the House of Commons.
The departure of Gyimah, one of the 21 and the second Tory MP to defect to the Lib Dems in the past fortnight, contributes to a sense of a party in crisis.
Former leader Cameron also laid into Johnson in his memoir "For The Record", saying he only backed Brexit in 2016 because it would woo the Tory faithful.
He "risked an outcome he didn't believe in because it would help his political career".
Cameron also accused Johnson and fellow Brexit campaigner Michael Gove, now a top minister, of "becoming ambassadors for the expert-trashing, truth-twisting age of populism".
Britain's Prime Minister Boris Johnson says he's very confident of getting a divorce deal from the EU
The Marvel Comics character Hulk is the destructive alter ego of scientist Bruce Banner who turns into the ferocious green giant when enraged or stressed
Key points from Britain's operation yellowhammer, the government's assessment of a worst-case scenario in a no-deal Brexit.
Prime Minister Boris Johnson compared Britain to the comic book character the Hulk, always escaping from tight situations