The anti-collusion campaigner, whose son Raymond Jnr was killed by a UVF gang which included police informers, made history by becoming the first unionist to address the republican gathering.

Mr McCord, who has defied numerous death threats, received a rapturous round of applause when he took to the podium.

He said: "To be the first Unionist to speak at the ard fheis is an honour.

"I wanted to bring something from a unionist Protestant culture, and I don't want to rub people's noses in it.

"It's something I'm proud of and it's my father's sash. And I'm going to wear it to give my speech in."

But last night a spokesman for the Orange Order gave Mr McCord's gesture a cool response.

"He is not the first person to make an inappropriate use of the Orange Order or its symbols to make a political point and he is unlikely to be the last,"he said.

Mr McCord continued: "A year ago a report came out from (former Police Ombudsman] Nuala O'Loan which proved collusion.

"Nuala O'Loan is a government appointee, yet the DUP in particular ignored it.

"I met Gerry Adams last year. He made a promise that he would raise my son's case with Downing Street. And he kept his promise. Jeffrey Donaldson gave me a promise four or five years ago that he would name the killers in Parliament.

"He must have a bad memory, because he's never named them."

Last night Mr Donaldson said he pledged to name the killers if Mr MrCord brought inconclusive evidence - and that evidence never came.

"It is a sad indictment of Mr McCord that he has used a Sinn Fein Ard Fheis to attack Unionists and praise republicans.

"Perhaps he should reflect on his new bedfellows and look at the record of the IRA for murder and destruction and ask himself: 'Are these the people best able to deal with the circumstances surrounding the murder of his son?'".