Cabinet to receive fresh Treasury damage forecasts for each Brexit option, reveals Philip Hammond

John McDonnell taunts ministers attacking him for ‘undermining capitalism’, saying: ‘They are doing a pretty good job themselves’

Cabinet ministers will be given fresh Treasury forecasts of the economic hit from various Brexit options, in a bid to end their bickering and agree a strategy.

Philip Hammond, the chancellor, revealed he would use the crunch Chequers meeting on Friday to focus minds by setting out the “implications of different potential routes forward”.

It is suggested the cabinet would be urged to consider the likely impact from staying aligned to the EU’s economic structures – or the higher cost of breaking free, as hardline Tories demand.

Mr Hammond revealed his plan as he vowed to use the showdown get-together to bang the drum for business and a Brexit that “protects our important supply chains, protects British jobs”.

The comments threaten a fresh clash with Boris Johnson, the foreign secretary, who reportedly responded to the growing warnings of economic damage by saying “f*** business” at an event for EU diplomats.

During Treasury questions in the Commons, John McDonnell, the shadow chancellor, taunted ministers attacking him for “undermining capitalism”, saying: “They are doing a pretty good job themselves.”

Mr Hammond’s assessment can be expected to take in the predicted costs of the two customs options put forward by No 10, which have triggered bitter cabinet rows.

Theresa May’s preferred “customs partnership” – which would see the UK collect EU tariffs – outraged pro-Brexit ministers and cannot be implemented before 2023 anyway.

But HMRC appeared to fatally undermine the rival technology-based “max fac” plan, revealing it would cost businesses up to an astonishing £20bn a year.

On Monday, No 10 said a third customs arrangement would be put forward at Chequers, but no details have been set out and even cabinet ministers are in the dark.

In the Commons, Mr McDonnell urged Mr Hammond to “tell us today the Treasury’s latest estimate of the cost of no deal, its consequences for the economy and the potential loss of jobs”.

In reply, Mr Hammond said: “I will be setting out for my colleagues, in the privacy of our cabinet meeting on Friday, the Treasury’s assessment – indeed, the cross-Whitehall economic group’s assessment – of the implications of potential routes forward.”

The chancellor repeated his promise to publish his assessments before MPs vote on the Brexit deal, to ensure they were “properly informed”.

And he slapped down cabinet ministers dismissing business fears, telling MPs: “I think the views of business, which is the great generator of employment and wealth and prosperity in our country, should always be taken very carefully into account.

“We have to listen to what business is telling us and make sure that we deliver a Brexit which delivers the needs of business.”

In January, leaked Treasury documents showed every mooted Brexit outcome would make Britain poorer.

The study predicted a no-deal Brexit, leaving Britain trading with Europe on World Trade Organisation terms, which would reduce growth by 8 per cent over 15 years.

Leaving with a Canada-style free trade agreement would see growth cut by 5 per cent, while even staying inside the single market would reduce growth by 2 per cent.

It was authorised by the prime minister, but ministers insisted it was “preliminary and partial” because it did not study the “bespoke” deal she has vowed to strike.