The Prime Minister is to meet all Northern Ireland's main parties as Stormont politicians continue to voice fears her anticipated parliamentary deal with the Democratic Unionists will undermine the peace process.
Theresa May will hold talks with the DUP, Sinn Fein, the SDLP, the Ulster Unionists 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.
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 DUP continue to hammer out the details of the deal with the Tories.
The announcement of any agreement is set to be delayed because of the tragic fire in a London tower block.
A DUP source said: "Our discussions are continuing."
Mr Brokenshire, who will also attend the Downing Street exchanges, characterised the meetings as a contribution to the three-week process to restore devolution.
"The UK government is offering whatever support we can, working alongside the Irish government, as appropriate, honouring our respective commitments in the Belfast Agreement to serve the interests of the whole community in Northern Ireland," he said.
"There is very little time left. An agreement to restore devolved powersharing government in Stormont must be reached by the 29 June deadline.
"Ultimately, I think the parties understand people voted in the March Assembly elections for a strong voice at Stormont.
"Northern Ireland's political leaders now have it in their hands to take control and shape a brighter future for everyone in Northern Ireland."
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.
The proposed deal would see the DUP back the Conservatives in votes on the Budget and confidence motions.
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 consensus.
With Brexit talks set to start in Brussels on Monday, former prime minister Mr Cameron said Mrs May would have to change her approach as a result of the election.
"It's going to be difficult. There's no doubt about that, but perhaps an opportunity to consult more widely with the other parties on how best we can achieve it," he said at a conference in Poland.
"I think there will be pressure for a softer Brexit," Mr Cameron added, saying that Parliament "deserves a say" on the issue.
He also suggested the Scottish Tories led by Ruth Davidson could add to the pressure on Mrs May to change course.
The Times reported that Chancellor Philip Hammond was preparing to fight for the UK to remain within the EU's customs union.
That would help safeguard jobs and trade with EU members but would severely restrict the UK's ability to strike its own trade deals around the world.
At a joint press conference with Mrs May in Paris on Tuesday night, France's President Emmanuel Macron suggested the door was still open for the UK to remain within the European Union.
Mrs May stressed Brexit would happen and the timetable remains on course.
She said: "I think there is a unity of purpose among people in the United Kingdom.
"It's a unity of purpose, having voted to leave the EU, that their Government gets on with that and makes a success of it, and we are committed to developing a deep and special partnership with the EU."