An Ulster Unionist councillor has defected to the Conservative Party in protest at the party's assembly links with PUP leader David Ervine.
Peter Bowles is a former Young Unionist chairman
Peter Bowles is a former Young Unionist chairman and represents Down District.
In an interview with the Sunday Times newspaper Mr Bowles said the UUP was "once the party of law and order but is now linked with the UVF".
He said the shooting of Mark Haddock and arrests over the Loughinisland massacre were the "last straws".
"Those guys (the UVF) haven't changed at all. They're still refusing to decommission," Mr Bowles said.
"A party with links to paramilitaries is not a party I want to be part of."
In a statement a UUP spokesperson said the party "regretted" Mr Bowles's decision.
"With regard to his latest concerns, the UUP remains committed to achieving change from loyalist and republican paramilitaries," he said.
"Talking about change will not in itself bring it about."
On Friday, Sylvia Hermon, the Ulster Unionists' only MP, called for the assembly link to be severed because of ongoing activity by the UVF, to which the PUP is connected.
David Ervine joined the Ulster Unionist group at the NI assembly
Lady Hermon warned the party had become "a hostage to fortune".
However, party leader Sir Reg Empey said while he "acknowledged and respected" Lady Hermon's views, he and others were "not prepared to walk away" from the deal.
The Ulster Unionists have come under widespread pressure after allowing Mr Ervine to join their assembly group.
The move would give them an extra ministerial seat at Sinn Fein's expense if a power-sharing executive is formed.
Sir Reg said in a statement on Friday that "the problem of loyalist paramilitaries had evolved over 35 years and this exercise cannot be completed in the space of three weeks - there is progress to be made".
"Having said that, we will know relatively quickly whether those with whom we are engaged with are being disingenuous.
"If they are, then naturally the position will have to be re-assessed and I will not hesitate to do so. This is not an unconditional arrangement."