A Brexit deal has been reached by negotiators in Brussels and will be the focus of a crunch Cabinet meeting on Wednesday afternoon.

Cabinet ministers were invited to read the papers relating to the draft deal on Tuesday night ahead of the special meeting of Theresa May's senior team "to decide on next steps".

The prime minister is currently meeting ministers for one-to-one talks as they are given sight of the draft agreement.

Leading  Brexiteers, such as Boris Johnson and Jacob Rees-Mogg, have urged the cabinet to reject the dump the draft agreement - which  is said to include commitments over citizens' rights after Brexit, a proposed 21-month transition period after the UK's departure on 29 March 2019 and details of the so-called £39bn "divorce bill".

And the a leading member of the DUP, the Northern Ireland unionist party that is propping up Theresa May’s government said they would vote down the Brexit deal she has struck with the EU as it was understood.

Special provisions thought to be included would lead to additional customs and regulatory checks between Britain and Northern Ireland, which the DUP have insisted they cannot support.

Scottish Secretary David Mundell said the draft Brexit agreement was "encouraging" but suggested the devil would be in the detail.

The Tory Cabinet Secretary said colleagues needed to "reflect on the detail", understood to be referring to the latest technical details of the Northern Irish backstop.

HeraldScotland: BIRMINGHAM, ENGLAND - OCTOBER 04:  Secretary of State for Scotland David Mundell speaks on stage on the third day of the Conservative Party Conference 2016 at the ICC Birmingham on October 4, 2016 in Birmingham, England.  Ministers and senior Party member

The Scottish government demanded to see details of the draft Brexit deal set to be discussed by UK ministers and the SNP's Michael Russell - the Scottish government's Brexit secretary - said the threat of a no-deal Brexit had not gone away

A Number 10 spokesman said: "Cabinet will meet at 2pm tomorrow to consider the draft agreement the negotiating teams have reached in Brussels and to decide on next steps."

A spokesman for chief EU negotiator Michel Barnier said the position had been set out earlier by European Commission vice president Frans Timmermans who said that while the talks were making progress "we are not there yet".

"The UK cabinet will meet tomorrow. We will take stock at the midday presser," the spokesman said.

HeraldScotland: Culture Secretary Fiona Hyslop

Scottish external affairs secretary Fiona Hyslop said: "We must see this deal, Scotland must not be forgotten".

Leading Brexiteers, such as Boris Johnson and Jacob Rees-Mogg, have urged the cabinet to reject the dump the draft agreement - which  is said to include commitments over citizens' rights after Brexit, a proposed 21-month transition period after the UK's departure on 29 March 2019 and details of the so-called £39bn "divorce bill".

The future of the border between Northern Ireland and the Republic of Ireland has been the last major issue to be dealt with amid heated debate over how to guarantee that there will not be physical checks reintroduced after Brexit.  

Irish broadcaster RTE reported that a deal involved one overall "backstop" in the form of a UK-wide customs arrangement - as sought by Mrs May - but with deeper provisions for Northern Ireland on customs and regulations.

A review mechanism is understood to be part of the text, but it is unclear whether that would meet the demands of Tory Brexiteers - including some in the Cabinet - who want the UK to be able to unilaterally walk away from the deal to prevent it becoming a permanent settlement.

HeraldScotland: DUP deputy leader Nigel Dodds said a budget must be set for Northern Ireland within the next fortnight. (Michael Cooper/PA)

DUP deputy leader Nigel Dodds says the deal as reported would leave Northern Ireland "subject to the rules and laws set in Brussels with no democratic input or any say".

He said: "We object to that on constitutional grounds that our laws would be made in Brussels, not in Westminster or Belfast.

"That is the fundamental red line."

He added: "If the reports are as we are hearing, then we can't possible vote for that."

And in a sign that Dublin may not be happy with the situation, a spokesman for Ireland's deputy premier Simon Coveney said: "Negotiations between the EU and UK on a withdrawal agreement are ongoing and have not concluded."

Former foreign secretary and hardline Brexiteer Boris Johnson said the leaked version of the deal he had seen would keep the UK in the customs union and the single market, is "as bad as it could possibly be" and  should be dumped.

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"For the first time in a thousand years, this Parliament will not have a say in the laws of this country," something which, he said, would be "utterly unacceptable".

"I hope the cabinet will do the right thing and I hope they will chuck it out," added Mr Johnson, who quit the cabinet over Theresa May's version of Brexit.  

HeraldScotland: Conservative MP and arch Brexiteer Jacob Rees-Mogg (Yui Mok/PA)

Leading Tory Brexiteer Jacob Rees-Mogg said  the UK would end up being a "slave state" and would keep the UK in the customs union and "de facto" the EU single market.

"I hope the cabinet will block it and I hope MPs will block it.  What we know of this deal is deeply unsatisfactory."

Former Tory leader Iain Duncan Smith has said that if reports of the deal's contents are true, the government is "breaking their own agreed position and will be bringing back something that is untenable".

He added that "if the cabinet agrees it, the party certainly won't".

Ministers have been seen entering and leaving Downing Street throughout the day after Tuesday's Cabinet meeting.

On his way into the joint ministerial council (JMC) at the Cabinet Office, Mr Mundell said he was "encouraged" and added: "That's what the Government has been working for all this time, to get a deal, and negotiators have worked incredibly hard to get us to this point, but we have to reflect on the detail and consider at Cabinet tomorrow.''

Health Secretary Matt Hancock was the first to arrive following confirmation that a deal had been reached, followed by Chief Whip Julian Smith and Transport Secretary Chris Grayling.

Confirmation that a deal had been reached by officials follows months of protracted talks in Brussels, with measures to prevent a hard border on the island of Ireland the main stumbling block.

The developments came after the Prime Minister told Cabinet on Tuesday morning that a "small number" of issues remained to be resolved and her de facto deputy David Lidington described a deal as "almost within touching distance".

Labour Party leader  Jeremy Corbyn said: "We will look at the details of what has been agreed when they are available, but from what we know of the shambolic handling of these negotiations, this is unlikely to be a good deal for the country.

HeraldScotland: Labour party leader Jeremy Corbyn leaves Labour party HQ in London, as he insisted he has created a "unifying" and "inclusive" shadow cabinet after putting the finishing touches to his top team. PRESS ASSOCIATION Photo. Picture date: M

“Labour has been clear from the beginning that we need a deal to support jobs and the economy - and that guarantees standards and protections. If this deal doesn’t meet our six tests and work for the whole country, then we will vote against it.”

Scottish constitutional relations secretary Michael Russell said on Tuesday evening that it was "completely unacceptable" that devolved administrations had still not seen the detail of any draft deal.

“We must be able to scrutinise the deal and understand its implications," he said.

“I am clear, however, that reaching agreement at technical level does not negate the threat posed by Brexit to jobs and living standards. The best way to avoid that is to stay in the EU, in line with how people in Scotland voted.

“If that is not possible, the only acceptable deal is one that keeps us in the Single Market as well as the Customs Union. That would resolve the backstop and ensure truly frictionless trade with the EU, which Scottish Government analysis shows is in the best interests of Scotland and the UK as a whole.”