THERESA May will come under intense pressure today to end the “alarm and uncertainty” over the UK Government’s move towards a so-called hard Brexit amid apparent cabinet splits, continuing rows over foreign workers and a fall-off in business investment.

David Davis, the Brexit secretary, is expected to give a statement to MPs this afternoon after the SNP set down an urgent Commons question, demanding he give answers over mounting concerns about the UK Government’s position; described by Sir Michael Fallon, the defence secretary, as “full Brexit”.

Ed Miliband, the former Labour leader, is believed to have begun talks with pro-EU Tory MPs in a bid to form a parliamentary alliance to force the Prime Minister to grant the Commons a vote on the UK Government’s planned approach to the Brexit talks due to begin by next spring.

Read more: Calling second Scottish independence vote might cause greater division than Brexit poll, warns leading academic

“Having claimed the referendum was about returning sovereignty to Britain, it would be a complete outrage if May were to determine the terms of Brexit without a mandate from parliament," insisted the former Labour leader.

“There is no mandate for hard Brexit and I don’t believe there is a majority in parliament for [it] either. Given the importance of these decisions for the UK economy…it has to be a matter for MPs,” he added.

Sir Keir Starmer, the shadow Brexit secretary, agreed that there had to be a “democratic grip” on the process, involving a Commons vote, while Nicky Morgan, the former Conservative education secretary, suggested there would be “common cause” among supporters of a soft Brexit, like herself, for a parliamentary mandate.

Thus far, however, Mrs May has set her face against such a move, believing it would simply be a means by which Remainers would seek to “subvert” the will of the people as expressed in the June 23 referendum.

Sir Michael declared: “We are all Brexiteers now. We're respecting the decision of the British people and we've got to make a success of it."

Read more: Calling second Scottish independence vote might cause greater division than Brexit poll, warns leading academic

As Tory insiders suggested the PM had been adopting a policy of “constructive ambiguity” on Brexit – one moment playing up greater migration controls, the next the need to maximise trade with Europe – deep splits appeared to be emerging among her cabinet colleagues.

Philip Hammond, who advocates a soft Brexit, has been accused of talking down Britain’s hopes of getting a good deal and attacked for his “relentless pessimism” by hard Brexiters. One cabinet colleague even went so far as to suggest the chancellor, who voted for Remain, could lose his job and should “watch his back”.

Iain Duncan Smith, the former work and pensions secretary, said on Sunday it was now “pretty clear” the UK would not remain a member of the single market.

His remarks will simply deepen cross-party alarm over the prospect of Britain being on the outside. Last week, First Minister Nicola Sturgeon, who wants to maintain the strongest ties with the EU, unexpectedly intervened to give tacit support to the possibility of a second EU poll when she said there “may well be” a case for one.

Tim Farron, the Liberal Democrat leader, said: “We’re going to[get] – it seems from the Conservative Party a reinterpretation of the result - if you like, a theft of the result for a hard Brexit that nobody voted for.”

Read more: Calling second Scottish independence vote might cause greater division than Brexit poll, warns leading academic

Today, following on from the plunge in the pound on currency markets, an authoritative poll of 7,000 firms from the British chambers of commerce highlights the uncertainty following the Brexit vote, showing it has hit business recruitment and investment plans.

Meantime, the Conservative Government, accused of adopting an “anti-foreigner agenda,” under pressure dropped its plan to force firms to publish the lists of their foreign workers. Justine Greening, the education secretary, said the lists would not be made public but kept confidential and used by ministers to help highlight skills shortages. Labour accused the Tories of being “in disarray”.

Stephen Gethins, the Nationalist spokesman on Europe, who has put down today's urgent Commons question on Brexit, said: “The Tory conference outlined an incredibly ugly vision of Brexit Britain; one of xenophobia and division. The ongoing splits in the Cabinet, which are being played out in the media in a series of off-the-record briefings, are leaving more questions than answers, causing yet more alarm and uncertainty.

“Mrs May says she will not give a running commentary but it is now starting to look like she has lost grip of all her warring government ministers who are fighting like cats in a sack with the cabinet splitting.”

The Fife MP claimed the Conservatives had “ramped up the disgraceful language of xenophobia and division” at their conference while at the same time top economists were warning the Brexit process could cost Scotland tens of thousands of jobs.

Mr Gethins added: ''It is depressing and dangerous and it is doubly worrying as they now look as if they are trying to drag Scotland out of the EU against its will without consulting or listening to the UK or Scottish parliaments.’’