Leading members of the Ulster Unionist and Democratic Unionist parties have distanced themselves from a statement released yesterday by the Loyalist Communities Council (LCC).
The LCC, which is backed by the UDA, UVF and Red Hand Commando, called Alliance votes 'nails in the Union's coffin'.
The group, which was backed at its launch by Jonathan Powell, Tony Blair's former chief of staff, echoed a call from the UDA-linked Ulster Political Research Group to back the DUP's Emma Little Pengelly in South Belfast.
The statement urged "every unionist and loyalist voter to ensure they turn out and vote for unionist candidates in the forthcoming general election".
LCC said it "particularly warns all unionists and loyalists against voting for Alliance party candidates".
"Many unionists think they can retain their unionism yet vote for Alliance candidates. They are sorely mistaken in that belief," it said.
"Any unionist who votes for the Alliance party is driving a nail into the coffin of the Union."
In response, the Alliance party issued its own statement challenging "those named and their parties to make clear whether they welcome this endorsement from paramilitary groups, including those still actively engaged in terrorism and criminality, or whether they reject it and repudiate the organisations behind it."
Ulster Unionist Party leader Robin Swann MLA quickly repudiated the LCC statement.
He said: "The Ulster Unionist Party is a party of law and order.
“We have not asked for the support of paramilitary organisations nor do we want the backing of organisations still engaged in paramilitary or criminal activity."
Speaking to the BBC on Tuesday, Sir Jeffrey Donaldson said the DUP is "a party of law and order" and does not want "the support of anyone or any organisation that continues to be involved in paramilitary or criminal activity".
On Monday night, Mike Nesbitt MLA, also rejected the LLC statement, tweeting: "As a candidate, I wish to state I did not ask for nor do I accept the LCC statement of support."
Also on Monday night, during an election debate on UTV, the DUP's Nigel Dodds emphasised that his party had always opposed paramilitarism.