Downing Street said an outline agreement on a “confidence and supply” arrangement had been reached which will be put to the Cabinet for discussion on Monday.
A “confidence and supply” arrangement is a far looser deal than a formal coalition or pact. It would mean the DUP backing the Government on its Budget and prevent it being brought down by motions of no confidence, but could potentially lead to other issues being decided on a vote-by-vote basis.
The development comes after Mrs May sent her Chief Whip Gavin Williamson to Belfast for talks with the DUP after the election left the Tories eight seats short of the 326 required for a majority.
The 10 MPs from the Northern Irish party could prove crucial in supporting the Conservatives on key votes after Thursday’s election saw Mrs May lose control of the Commons.
A Number 10 spokesman said: ‘We can confirm that the Democratic Unionist Party have agreed to the principles of an outline agreement to support the Conservative Government on a confidence and supply basis when Parliament returns next week.
‘We welcome this commitment, which can provide the stability and certainty the whole country requires as we embark on Brexit and beyond.
“The details will be put forward for discussion and agreement at a Cabinet meeting on Monday.”