SCOTLAND will lose out on almost £3 billion for public services after Theresa May’s “grubby” deal with the Democratic Unionist Party to keep her in power bypassed the usual process for distributing UK Government funds, the SNP has claimed.

Ian Blackford, the Nationalist leader at Westminster, insisted Scotland should get "its fair share" under the Barnett Formula and said: "For years the Tories have been cutting budgets and services but suddenly they have found a magic money tree to help them stay in power."

Nicola Sturgeon, the First Minister, noted: "In concluding this grubby, shameless deal, the Tories have shown that they will stop at nothing to hold on to power; even sacrificing the very basic principles of devolution.”

For Labour, Emily Thornberry also denounced the Government's £1bn deal with the Northern Irish party as “shabby and reckless,” saying while the Good Friday Agreement was a model of peace-building around the world, it was fragile and relied on trust, good faith and the impartiality of Whitehall.

"So for the Government to be putting such an agreement in jeopardy just to prop up this dismal Prime Minister is nothing short of a disgrace," she declared.

But Damian Green, the first secretary of state, said Ms Thornberry was “fundamentally wrong” and stressed how the extra money would go to all communities in Northern Ireland and so made it more likely a power-sharing executive at Stormont would be formed this week.

He also hit back at the SNP’s attacks, noting how Scotland itself had benefited greatly from Government funding outside the Barnett Formula, citing the £500 million City Deal for Glasgow, £5m for the V&A in Dundee and £5m for Glasgow School of Art, among others.

“Huge amounts of money are going to Scotland from outside as well as inside the Barnett Formula. If the Scottish National party does not recognise that, I suggest that its members go back to their constituencies and find out what is happening in Scotland,” insisted Mr Green.

Nigel Dodds, the DUP’s deputy leader, slammed some of the "faux outrage" over the deal as "hypocrisy of the highest order," warning that his party might publish its correspondence with Labour and the SNP from previous general elections.

The MP for Belfast North insisted the Con-DUP deal was good for Northern Ireland and good for the United Kingdom.

The "confidence and supply" agreement is intended to last until 2022 and will mean the DUP will guarantee its 10 MPs will vote with the Government on the Queen's Speech, the Budget as well as legislation relating to Brexit and national security.

The DUP's support in votes which are not covered by this arrangement will be agreed "on a case-by-case basis".

The Prime Minister, who said the two parties “share many values, stressed how the agreement would "enable us to work together in the interests of the whole United Kingdom, give us the certainty we require as we embark on our departure from the European Union, and help us build a stronger and fairer society at home".

The £1bn for infrastructure and health spending together with enhanced flexibility on almost £500m of previously allocated cash is contingent on the DUP and Sinn Fein agreeing to revive the Stormont executive by Thursday’s deadline.

If this fails, then extra money for Northern Ireland, which, it is thought, would be much less than the £1bn agreed, would be distributed by a committee in London after direct rule is re-introduced. This arrangement appears to give both sides in Northern Ireland an incentive to revive its power-sharing body.

Gerry Adams, the Sinn Fein President, made clear the only forum that could guarantee funds were distributed in a “fair way” was the Stormont executive.

The developments came as the Prime Minister set out more details on her plans for the status of EU citizens living in the UK post Brexit, saying: “We want you to stay” and insisting that no families would be split up.

But Jeremy Corbyn for Labour denounced the Tories for being “prepared to use people as bargaining chips" in the Brexit negotiations.

The Government also confirmed it would ask Holyrood to grant a Legislative Consent Motion[LCM] on the Repeal Bill, seeking the Scottish Parliament’s agreement that Westminster would legislate for Scotland on the issue.

The SNP’s Stephen Gethins welcomed the confirmation given by David Davis, the Brexit secretary, during a Commons debate, but called on him to publish the full details and “how the devolved administrations will be involved in Brexit negotiations going forward”.

Over the weekend, Mr Davis warned the Scottish Government not to do anything to block the passing of the Brexit legislation as this would leave a “black hole” in UK law and make it unworkable.

A senior Whitehall source said the Government was “confident” MSPs would grant the LCM.

He said: “There might generally be some sound and fury on the way but we don’t expect the SNP to push this to destruction.”

Yet if for whatever reason MSPs refused to grant an LCM, this would spark a constitutional crisis between Edinburgh and London, causing a potentially serious delay to Mrs May’s legislative timetable.