Tory MPs warn Boris Johnson and Jeremy Hunt against making ‘unachievable’ promises

The One Nation group of centre-ground MPs calls on the leadership contenders to rule out any pact with Nigel Farage

More than 70 Conservative MPs have issued a warning to leadership contenders Boris Johnson and Jeremy Hunt not to commit themselves to “unachievable” promises during the campaign to replace Theresa May.

A letter signed by former ministers Nicky Morgan and Sir Nicholas Soames on behalf of the One Nation group of MPs said that the candidates need to provide “far more detail” about their plans to prevent a no-deal Brexit damaging the UK economy.

And they urged them to stand by commitments not to make deals with Nigel Farage’s Brexit Party or to suspend parliament to force through a no-deal Brexit.

The letter emerged as a series of moderate Cabinet ministers issued warnings about the prospect of leaving the European Union without an agreement.

Theresa May’s effective deputy David Lidington said he would not serve in any government that would intentionally leave without a deal on 31 October, as Mr Johnson is prepared to do. Warning English voters not to take the Union with Scotland, Wales and Northern Ireland for granted, Mr Lidington said a no-deal would be “very bad for the Union both economically and politically”.

Chancellor Philip Hammond, expected to be sacked by either of the leadership contenders later this month, told the BBC’s Political Thinking podcast it would be “shocking” if Ms May’s successor sought to “sideline” the House of Commons.

"The Commons has been clear already that it does not support a no-deal exit. That is my position, and as a backbencher I will continue to argue against a no-deal exit," said Mr Hammond.

And justice secretary David Gauke insisted that “a way will be found” to block a no-deal Brexit, telling The House magazine: “I do think that parliament will find mechanisms to try to stop this from happening.”

Johnson and Hunt have made a string of spending promises during the campaign to replace Ms May, including a new pledge from the former London mayor to cut stamp duty to get the housing market moving.

The One Nation Tories’ letter warned them: “Many of your colleagues are increasingly concerned about the rhetoric being used in the leadership contest and the unachievable promises being made.”

With both candidates making clear that they are ready to leave the EU on World Trade Organisation terms if an acceptable deal cannot be secured, the group said that they need to spell out how they would prepare the UK for such an outcome.

“We need far more detail from you now on planned tariff schedules, the mitigation plans you have for those industry sectors and regions most likely to be adversely impacted, any bilateral or multilateral contingency arrangements you anticipate need to be in place during the early part of November and any details you have now for an emergency no-deal Budget,” they said.

Mr Johnson has been urged by prominent eurosceptic backer Steve Baker to forge a pact with Mr Farage’s party if a general election comes before Brexit has been delivered.

But the One Nation group made clear this would be unacceptable.

They told both candidates: “We ask you to stand by the commitment you made at at the One Nation hustings last month to rule out any deals with the Brexit Party or the involvement in any way of Nigel Farage in any negotiations with the EU on Brexit and in your future government, and not seek to prorogue parliament as a way of securing a no-deal outcome to Brexit.”