The Prime Minister is to hold talks with political leaders from Northern Ireland in a bid to allay fears the anticipated parliamentary deal with the Democratic Unionists will undermine the peace process.
Theresa May will meet with Sinn Fein, the Ulster Unionists, the SDLP and Alliance Party in separate engagements at Downing Street on Thursday afternoon.
The move comes amid concerns the Government will compromise its stated impartiality in the region if it enters a confidence and supply deal with the DUP at Westminster.
Sir John Major is one of those urging caution.
Sinn Fein, the SDLP and Alliance have all made clear Northern Ireland Secretary James Brokenshire cannot chair the ongoing process to restore powersharing at Stormont due to their perception he has a conflict of interest.
While the DUP continue to hammer out the details of the arrangement with the Tories, the other four main parties at Stormont confirmed they would be meeting Mrs May on Thursday.
The 1998 Good Friday Agreement commits the UK and Irish Governments to demonstrate “rigorous impartiality” in their dealings with the different political traditions in Northern Ireland.
Sinn Fein’s Stormont leader Michelle O’Neill said: “I will be making it very clear that any deal between the Tories and the DUP cannot be allowed to undermine the Good Friday and subsequent agreements.”
The announcement of any deal between the DUP and Conservatives will likely be delayed because of the tragic fire in a London tower block.
Mrs May needs the votes of the DUP’s 10 MPs to prop up her minority administration as she hopes to steer government business, including crucial measures on Brexit, through the Commons.
A Conservative source said there was so far no deal to announce and that a decision on the timing of any announcement would have to wait until an agreement was finalised.
Ministers have already said that the Queen’s Speech may have to be set back from its scheduled date of next Monday June 19, because of the ongoing negotiations.
Mrs May is coming under intense pressure to change her approach to leaving the European Union, with predecessor David Cameron among those suggesting a softer stance with a greater effort to seek a consensus.
Talks with the DUP broke up on Tuesday night without an agreement, but Mrs May said the discussions had been “productive”.
DUP leader Arlene Foster, who travelled to Westminster for talks with the Tories on Tuesday, said she hoped a deal could be reached “sooner rather than later”.
The proposed deal would see the DUP back the Conservatives in votes on the Budget and confidence motions.
For Labour, shadow business secretary Rebecca Long-Bailey said the prospect of a Conservative-DUP deal was “worrying”, telling BBC Radio 4’s Today programme: “It would create a lot of instability in terms of the peace process in Northern Ireland.”