Theresa May has been accused of jeopardising peace in Northern Ireland, after reaching a £1 billion deal with the Democratic Unionist Party to prop up her minority Government.
The deal struck in 10 Downing Street after negotiations stretching 18 days since the June 8 General Election also saw the Conservatives formally ditch plans to abolish the triple-lock protection for state pensions and means-test the winter fuel payment during this Parliament.
Under a "confidence and supply" arrangement intended to last until 2022, the DUP guaranteed that its 10 MPs will vote with the Government on the Queen's Speech, the Budget, and legislation relating to Brexit and national security.
Together with the 317 Tory MPs remaining after Mrs May's disastrous decision to call a snap election, this will allow the Prime Minister to pass the 326 figure required for an absolute majority in the House of Commons, ensuring her victory in key divisions and protecting her Government from collapse.
Speaking after talks in Number 10 with DUP leader Arlene Foster, Mrs May said the two parties "share many values" and the agreement was "a very good one".
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", said the Prime Minister.
Mrs Foster said she was "delighted" with a package which includes £1 billion of new funding for infrastructure and health, along with enhanced flexibility on almost £500 million of previously allocated cash.
The cash will go to the Northern Ireland executive if the devolved institutions are restored by the deadline of June 29. If direct rule is reimposed, the money would remain available, but would be controlled from London.
There were immediate demands for similar largesse for other parts of the UK, with the Welsh executive saying the principality was due almost £1.7 billion under the so-called "Barnett formula" which governs how money is distributed between the four nations.
Welsh First Minister Carwyn Jones described the payment as a "straight bung to keep a weak Prime Minister and a faltering Government in office".
And the Scottish National Party's Westminster leader Ian Blackford insisted Scotland should get "its fair share".
Denouncing the "grubby" deal with the DUP, Mr Blackford 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."
Downing Street said the Barnett formula does not apply to the new money as it is being provided as an addition to the Northern Ireland Executive's block grant.
Labour branded the deal "shabby and reckless", and warned it would undermine the trust in the impartiality of the British Government which was vital to the implementation of the Good Friday Agreement.
"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," shadow foreign secretary Emily Thornberry told the House of Commons.
In an attempt to allay concerns about the impact on the peace process, the deal makes clear that Conservatives remain committed to the restoration of power-sharing and that the DUP will have "no involvement in the UK Government's role in political talks in Northern Ireland".
Sinn Fein said the DUP were effectively supporting continued austerity and cuts, as well as "a blank cheque for a Tory Brexit which threatens the Good Friday Agreement".
The party's president Gerry Adams raised concerns about the commitment contained in the deal for Tories and the DUP to support the implementation of the Armed Forces Covenant throughout the UK. Sinn Fein will "resolutely oppose" any preferential treatment for British soldiers on services like healthcare, education and housing under the terms of the Covenant, as they do on the mainland, he said.
Outlining the terms of the agreement in the House of Commons, First Secretary of State Damian Green said that only the Conservatives had "the ability and legitimacy to lead the Government our country needs", adding: "As the party with the most seats at the General Election, the Conservative Party had a duty to form a government.
"It is right that we talked to other parties to seek to ensure that the Government can provide the competence the country needs at this crucial time."
Mr Green said the agreement, signed in 10 Downing Street by Tory chief whip Gavin Williamson and the DUP's Sir Jeffrey Donaldson, should help to break the deadlock at Stormont which has meant there has been no power-sharing executive since elections in March.
Mr Adams said any extra money for Northern Ireland was a good thing, and the restoration of power-sharing was the only way to ensure it was fairly distributed.
"We may be able to say well done Arlene, when we have the executive in place," he said.
The agreement will remain in place for the length of this Parliament, due to end in 2022, and can be reviewed "by the mutual consent of both parties", the document says.
But Downing Street made clear that the money will not be withdrawn if the DUP fails to live up to voting commitments.
The DUP's support in votes which are not covered by the confidence and supply arrangements will be agreed "on a case-by-case basis".