A meeting of the Brexit “war Cabinet” today is unlikely to achieve a breakthrough on Britain’s aims for its “end state” relationship with the EU, a senior minister has admitted.

Theresa May is under huge pressure to end the confusion over her negotiating stance, with business leaders threatening to pull investment from the UK if she dithers for more than a fortnight longer.

But, speaking ahead of the two-day meeting, Business Secretary Greg Clark twice failed to say that senior Cabinet ministers – who have been rowing in public – would be able to end their divisions.

Instead, he argued that business leaders had been given the reassurance they needed with the decision to pursue a transition period, keeping existing trading rules for about two years.

Mr Clark said a “series of meetings” of the inner Cabinet would be needed before agreement was reached on a long-term deal that “meets our objectives”.

Pointing instead to the certainty to be provided by the transition period, he said: “That was a very important request from business and we were able to achieve that.”

The comments suggest that this week’s get-togethers – discussing immigration and Northern Ireland today and trade tomorrow – are merely a taster for further intense talks later this month.

The Prime Minister has been accused of still trying to “have her cake and eat it”, by vowing to leave the EU’s single market and customs union while demanding tariff-free and frictionless trade.

Her task is to somehow achieve a consensus among the ten other ministers in the “war Cabinet”, who include big figures from both sides of the bitter Tory civil war on Europe.

The biggest issues facing UK on leaving EU Show all 8 1 /8 The biggest issues facing UK on leaving EU The biggest issues facing UK on leaving EU Post-Brexit immigration workers sorting radishes on a production line at a farm in Norfolk. One possible post-Brexit immigration scheme could struggle to channel workers towards less attractive roles - while another may heighten the risk of labour exploitation, a new report warns. PA The biggest issues facing UK on leaving EU Customs union A key point in the negotiations remains Britain's access to, or withdrawal from, the EU customs union. Since the referendum there has been hot debate over the meaning of Brexit: would it entail a full withdrawal from the existing agreement, known as hard Brexit, or the soft version in which we would remain part of a common customs area for most goods, as Turkey does? No 10 has so far insisted that “Brexit means Brexit” and that Britain will be leaving the customs union, but may be inclined to change its position once the potential risks to the UK’s economic outlook become clearer. Alamy The biggest issues facing UK on leaving EU Northern Ireland-Irish border Though progress was made last year, there has still been no solid agreement on whether there should be a hard border between Northern Ireland and the Republic of Ireland. To ensure borderless travel on the island, the countries must be in regulatory alignment and therefore adhere to the same rules as the customs union. In December, the Conservative Party’s coalition partners, the DUP, refused a draft agreement that would place the UK/EU border in the Irish Sea due to its potential to undermine the union. May has promised that would not be the case and has suggested that a “specific solution” would need to be found. Getty The biggest issues facing UK on leaving EU Transition period Despite protests from a small number of Conservative MPs, the Government and the EU are largely in agreement that a transitional period is needed after Brexit. The talks, however, have reached an impasse. Though May has agreed that the UK will continue to contribute to the EU budget until 2021, the PM wants to be able to select which laws made during this time the UK will have to adhere to. Chief negotiator Michel Barnier has said the UK must adopt all of the laws passed during the transition, without any input from British ministers or MEPs. EPA The biggest issues facing UK on leaving EU Rights of EU citizens living the UK The Prime Minister has promised EU citizens already living in the UK the right to live and work here after Brexit, but the rights of those who arrive after Brexit day remains unclear. May insists that those who arrive during the transition period should not be allowed to stay, whereas the EU believe the cut-off point should be later. Getty The biggest issues facing UK on leaving EU Future trade agreement (with the EU) Despite this being a key issue in negotiations, the Government has yet to lay out exactly what it wants from a trade deal with the EU. Infighting within the Cabinet has prevented a solid position from being reached, with some MPs content that "no deal is better than a bad deal" while others rally behind single market access. The EU has already confirmed that access to the single market would be impossible without the UK remaining in the customs union. Getty The biggest issues facing UK on leaving EU Future trade agreements (internationally) The Government has already begun trying to woo foreign leaders into prospective trade agreements, with various high profile state visits to China, India and Canada for May, and the now infamous invitation to US President Donald Trump to visit London. However the UK cannot make trade agreements with another country while it is still a member of the EU, and the potential loss of trade with the world's major powers is a source of anxiety for the PM. The EU has said the UK cannot secure trade deals during the transition period. EPA The biggest issues facing UK on leaving EU Financial services Banks in the UK will be hit hard regardless of the Brexit outcome. The EU has refused to give British banks passporting rights to trade within the EU, dashing hopes of a special City deal. However according to new reports Germany has suggested allowing trade on the condition that the UK continues paying into the EU budget even after the transition period. Getty

Mr Hammond has openly called for only “very modest” changes after Brexit, while Mr Johnson and Dr Fox have attacked anything short of a clean break from EU’s economic structures.

As The Independent reveals today, Mr Johnson is also planning a big speech on Brexit next week, which may trigger further damaging public fall-outs.

Overnight, the British Chambers of Commerce published an open letter to Mrs May, making clear its patience was wearing thin and setting a deadline of two weeks for a decision.

“Businesses need those elected to govern our country to make choices – and to deliver a clear, unequivocal statement of intent,” the organisation’s director general and president wrote.

Brussels has also laid bare its frustration over Britain’s failure to spell out what it wants. “The time has come to make a choice,” Michel Barnier, the EU’s chief Brexit negotiator, said in No 10 this week.

And Keir Starmer, Labour’s spokesman, said: “Sixteen months after Theresa May set out her red lines on Brexit, it is obvious they stand in the way of a progressive partnership with the EU capable of delivering the benefits of the single market and the customs union.