Chancellor of the exchequer Philip Hammond has vowed to oppose a no-deal Brexit from the back benches, according to The Times.
As well as a speech to civil servants last week, the chancellor also used his address at an all-staff Treasury meeting to tell his department they should not change their advice on the consequences of a no-deal.
He said earlier this month that in the event of a disruptive no-deal exit, “there will be a hit to the exchequer of about £90bn”.
It is understood Hammond told officials: “It has not escaped my attention that the next prime minister’s majority will only be three, and that I will be a backbencher… Parliament is going to be where the action is, and I will be there on the back benches.”
It is expected Hammond will lose his role as a Conservative front-bencher after 21 years when the new prime minister is announced next Tuesday (23 July).
Current home secretary Sajid Javid is set to be the favourite to succeed him if Boris Johnson is successful in his campaign.
Hammond will join justice secretary David Gauke, international development secretary Rory Stewart and business secretary Greg Clark, in being a vocal anti-no-deal member of parliament.
A source present at the speech last week told The Times: “The chancellor made clear that the Treasury must not change its advice on Brexit to suit the next prime minister or chancellor’s political priorities, which received a huge round of applause.”
Meanwhile, the chancellor told BBC Panorama that if the UK leaves without a deal, the EU will control many of the levers, including what happens at the port in Calais.
Asked if the UK can control Brexit, he said to the BBC: “We can’t because many of the levers are held by others – the EU 27 or private business. We can seek to persuade them but we can’t control it.”
Leadership favourite Johnson has pledged the UK will leave the EU on 31 October regardless of having a deal, meanwhile rival Jeremy Hunt has said he can negotiate a new deal by the end of September and expects the UK will leave the EU before Christmas.