Former Prime Minister John Major has warned Conservatives against a formal tie-up with Northern Ireland's Democratic Unionist Party even as talks are ongoing in Downing Street today.
In a blow to the Tories' hopes of agreeing a "supply and confidence" deal, Major warned any agreement could endanger the Northern Irish peace process, adding that he was "concerned, wary and dubious" about how a deal would affect the UK's ability appear impartial.
"The only honest broker can be the UK government, and the question arises, if they cease to be seen as such by part of the community in Northern Ireland, one can't be certain how events will unwind. And that worries me a great deal about the peace process," Major told BBC Radio's World at One.
DUP leader Arlene Foster arrived in Westminster for talks with Tory leader Theresa May earlier this afternoon, with the Conservatives needing the Unionist party's numbers in order to be sure of avoiding a defeat on the Queen's Speech.
However, Major said running a minority government was "an option well worth considering", arguing that even an informal alliance was "bound" to strain relations with the Irish government.
The former Tory leader, who had his own experience of leading a government with limited authority, added that the Tories should counterbalance any agreement with evidence of a cross-party approach on Brexit.
"If the government do form a deal with the DUP, and I can see they will might feel that they have to, it is doubly important, trebly important, to consult on Brexit widely both in and out of parliament," Major said.
"[That way] People would see that there isn't going to be disproportionate pressure from one part of the United Kingdom."