Philip Hammond has warned of significant disruption to the UK economy if Britain leaves the EU without a deal in March, but has said a no-deal Brexit was “a default that we could find ourselves in”.

Speaking the day after he told nervous business leaders to accept the result of the referendum, the chancellor said the disruption caused by leaving the EU without a deal would “settle down”.

“We will find ways of managing things like the additional time it takes for trucks to get through the border,” he told the BBC’s Today programme.

“But it might take us quite a while to sort that out. So there will be a short-term impact through disruption. There will be a long-term impact through a reduction in the size of our economy.”

He added: “I clearly do not believe that making a choice to leave without a deal would be a responsible thing to do, but I recognise that that is potentially a default that we could find ourselves in.”

Addressing a Confederation of British Industry (CBI) lunch in Davos, Switzerland, on Thursday, Hammond said companies had to accept that changes were coming – such as an end to the free movement of people and business models built on a supply of cheap labour.

Speaking to the BBC from Davos on Friday morning, the French finance minister, Bruno Le Maire, said the country was preparing for a no-deal Brexit. “We hope for the best, but we also prepare for the worst,” he said.

“It is also my responsibility as the minister in charge of finance and the economy to prepare for the worst and, of course, a Brexit without any agreement, without a deal, would be a catastrophe for the UK, but would also have negative consequences for all European countries.”

Le Maire was asked about reports that some EU countries were putting pressure on the European commission to be more generous to the UK in the event of no deal and allow UK hauliers the right to operate on the continent. He said: “You can’t be out of the EU and get all the benefits of the single market. That’s a clear red line for France.”

The chancellor said on Friday that he did not think the EU would change its fundamental position around the backstop, but that he had heard that European politicians were thinking very hard about where their red lines had been drawn.

Pressure has mounted on Theresa May to rule out a no-deal Brexit in recent days, with the Airbus chief executive, Tom Enders, saying on Thursday morning: “Please don’t listen to the Brexiteers’ madness, which asserts that ‘because we have huge plants here we will not move and we will always be here’. They are wrong.”

His comments were praised by the business minister Richard Harrington at a German Industry UK gathering in London later that day. He said he would be happy to be sacked for speaking out. “I really don’t believe in this idea,” he said of a no-deal Brexit. “I am very happy to be public about it and very happy if the prime minister decides I am not the right person to do the business industry job.”

The work and pensions secretary, Amber Rudd, hinted on Thursday night she could resign from the government to stop the UK crashing out of the EU without an agreement.

The prominent remain supporter told BBC Two’s Newsnight she was going to “wait and see” if May allows a free vote on a series of amendments to her Brexit “plan B” on Tuesday.

Asked repeatedly if she would quit the cabinet to back a bid by Labour’s Yvette Cooper to extend article 50 unless a deal was reached by the end of February, Rudd said: “At this stage I’m going to stick to trying to persuade the government to allow it to be a free vote.”

The Queen made what has been interpreted as a rare intervention in the Brexit debate on Thursday in a speech to mark the centenary of the Sandringham Women’s Institute, which she joined in 1943 aged 17.

The monarch called for “common ground” and “never losing sight of the bigger picture” and she spoke of the virtues of “respecting” the other person’s point of view.

She said: “Every generation faces fresh challenges and opportunities. As we look for new answers in the modern age, I for one prefer the tried and tested recipes, like speaking well of each other and respecting different points of view; coming together to seek out the common ground; and never losing sight of the bigger picture.

“To me, these approaches are timeless, and I commend them to everyone.”