In a further ramping up of pressure on Johnson ahead of his expecting crowning as prime minister next week, Hammond said he would “do everything from the backbench to make sure that parliament blocks a disorderly Brexit”.
The chancellor also appeared to take aim at Brexiteers on his own side, who he described as “very loud, rude and inconsiderate” in an interview with Le Monde and Süddeutsche Zeitung.
Hammond was one of four cabinet ministers who took the extraordinary step of rebelling against the government on Thursday to back an amendment which will block Johnson from suspending parliament to force through no deal.
Johnson has promised to leave the EU “do or die” by the October 31 Article 50 deadline and has taken a hardline stance on renegotiating Theresa May’s rejected withdrawal agreement, sparking fears among many MPs that he will end up backing a no-deal Brexit.
Hammond, along with fellow rebels Greg Clark and David Gauke, are said to be ready to quit the cabinet the second Johnson takes office next week.
And in a further provocation of the likely incoming PM, Hammond told Le Monde, the French newspaper and Süddeutsche Zeitung, of Germany: “I will do everything from the backbench to make sure that Parliament blocks a disorderly Brexit .
“I will argue that there is no EU exit without parliament’s approval. We should make another honest attempt to reach an agreement. If we can not find a solution in the House of Commons, we may need to consult the British people again, in one form or another.”
Asked to rule out supporting a vote of no confidence against Johnson, Hammond said: “I do not exclude anything at the moment.”
Hammond also criticised Brexiteers, who he accused of trying to provoke the EU into kicking the UK out without a deal.
In comments aimed at EU leaders, he said: “Some of my compatriots are deliberately very loud, rude and inconsiderate. Some are working towards Europeans saying they are so content to tell Britain to leave. But please, do not listen to the few noisemakers.”
The chancellor also suggested Johnson was betraying his own principles by taking a hardline approach to Brexit.
“He is actually a more complex personality than it sometimes seems,” he said.
“He is a mainstream conservative on all topics except Brexit. I very much regret his attitude to Brexit. His own story, which is multicultural, multinational and liberal, speaks for itself.”
Another frontbencher, Health Minister Stephen Hammond, also signalled he could be willing to vote down a Johnson administration in a no-confidence vote if it pursued a no-deal exit.
Asked whether he was prepared to press the “nuclear button” with such a vote, he repeatedly cited putting the national interest before personal ambitions.
“I hope we never get there, but I think a lot of people were taught that you must put the interest of the country before yourself,” the Wimbledon MP told BBC Radio 4′s Today programme.
“I don’t think we will get there actually, and I’m pretty certain, as a Conservative, that I would be very, very, very cautious about ever doing that.”
He added: “I think it’s really important that, at this historic stage in this country’s lifetime in modern politics, that politicians put aside any of their own personal ambitions or views and actually make sure they do the right thing as they see it for the country.”
But Johnson ally Jacob Rees-Mogg suggested the chances of Tory MPs voting to bring down their own government was slim, accusing colleagues of trying to “bluff” their way to preventing Breixt.
The chair of the Brexiteer European Research Group said: “It’s quite difficult unless they have a vote of no confidence and they don’t want to do that because they would lose their seats because any Conservatives who voted against the Government on a vote of no confidence would be automatically deprived of the whip.”