DUP DEPUTY leader Nigel Dodds has rejected calls for senior party figures to resign over their handling of Brexit.
The former North Belfast MP described as "pathetic" Ulster Unionist Lord Empey's call for Arlene Foster and others to "consider their positions".
The intra-unionist spat came in the wake of UK-EU's agreement on the Northern Ireland Protocol, a move that puts a so-called border in the Irish Sea.
Lord Empey said the DUP had demonstrated a "dereliction of their duty" by failing to protect the union.
"The fact is, on the October 2 2019, they (DUP) agreed a border in the Irish Sea – now how could any unionists do that?" the former UUP leader asked.
"They pulled away from that two weeks later but the damage was done, the floodgates were open and Brussels and Dublin took advantage."
The DUP deputy leader – now Lord Dodds of Duncairn – attacked his fellow peer's role in the Good Friday Agreement negotiations.
"It is pathetic really for someone like Lord Empey, who basically negotiated an agreement that released terrorist prisoners on to our streets, destroyed the RUC and put Sinn Féin in government without any decommissioning, whilst they were still murdering people - the IRA were doing that - to lecture other people," Mr Dodds told the BBC.
"The reality is that he is wrong and it is a falsehood and a lie to say the DUP agreed a regulator border."
Lord Dodds said his party only agreed to regulatory difference if the assembly and the executive agreed to it.
"A mixture of whingeing and pathetic falsehoods will not deter us in the DUP from doing what is right for Northern Ireland, which is grappling with the issues," he said.
But an angry Lord Empey stood by his assertions in a later interview with Radio Ulster.
"I was called a liar this morning and a purveyor of falsehoods," he said.
"The position I am simply putting to Nigel Dodds and his colleagues is that on October 2 last year they agreed a border in the Irish Sea and if I am wrong on that you can get your researchers to check it out, read the document I referred to – It is there in black and white; it is factual, I wish it wasn't."
The former East Belfast MLA said unionism needed to pull together to challenge any apparent breaches of the Good Friday Agreement arising from the protocol.
