Sinn Fein leader Gerry Adams has blasted any deal between the DUP and Conservative Party, saying an alliance would lead to a “coalition of chaos”.
Mr Adams expressed worry that a deal could “undercut” the process of restoring the government in Northern Ireland and would put the Good Friday Agreement at risk.
The DUP is set to prop up the Conservative Party in a new British Government, with Theresa May having failed to win a majority in last week’s General Election.
Political parties in Northern Ireland are currently working to restore the executive government after it broke down in January, with Mr Adams saying he would oppose any coalition that endangered the process.
Speaking at a press conference in Belfast, he said: “I would hardly call that sort of arrangement between the DUP and the English Tories stable.
“That’s the very least it is – it’s a coalition of chaos for the times ahead.”
Irish Prime Minister Enda Kenny has sought assurances from Mrs May that “nothing should happen” to endanger the Good Friday Agreement.
The DUP is the only major political party in the Northern Ireland to oppose the agreement, which led to the creation of the Northern Irish government.
The party won 10 MPs in the General Election, who could prove pivotal in major political decisions, having already agreed a “deal in principle” with the Tories.
The Queen’s Speech was today delayed while talks between the two parties take place.
Mr Adams said: “The issues are very very clear cut, they are all rights issues. They’re all the subject of previous agreements that all the party’s signed up to.
He added: “We’re looking forward especially to the meeting with the DUP and the DUP leader. They too have had a good election and we congratulate them on that.
“I know their focus is on what’s happening in London and it’s very important to say that we don’t believe that any deal between the DUP here and the English Tories will be good for the people here.
“Any deal which undercuts in any way the process here or the Good Friday and other agreements is one that has to be opposed by progressives.”
The Conservative Party has come under criticism for aligning with the socially hardline DUP, which has a right-wing stance on issues such gay rights and abortion.
On Saturday, hundreds of anti-DUP protesters marched on Downing Street against the "hateful" alliance between Mrs May and the DUP.
Mr Adams added: “It’s an interesting time in both British politics and in Irish politics. Remember the train coming down the track is Brexit and we all of us need to be match fit to face up to the responsibilities there.”
