The rivalry between the two main unionist parties has turned personal.
Tom Elliott, the UUP leader, has demanded that Peter Robinson apologise for calling him a liar over his interpretation of a Belfast Telegraph interview.
The row first blew up during a leaders’ debate last Thursday in which Mr Elliott accused Mr Robinson of saying Caitriona Ruane of Sinn Fein was “great”.
Today the latest round will be fought out at a UUP Press conference in which Mr Elliott promises he “will deal with Peter Robinson's praise of Sinn Fein ministers”.
Michael McGimpsey and Danny Kennedy, the two UUP ministers in the last Executive, will flank him and tell of their own experiences.
The aim is clearly to stoke the dispute and portray the DUP as too close to Sinn Fein at a moment when the party needs to distance itself from republicanism in order to mop up UUP votes.
Elliott will say that Sinn Fein and the DUP effectively controlled Executive business between them.
This is a toxic accusation to introduce as the DUP seeks votes to help it defeat Sinn Fein and “bring unionists together to maximise unionism’s strength and influence”.
During last Thursday’s UTV debate, Mr Elliott turned to Mr Robinson and said “Peter — you said: ‘Oh, the Minister for Education's great!'“
Mr Robinson replied: “I said nothing of the sort. Show me the quote.” The exchange made compulsive viewing, with Mr Elliott smiling and laughing while Mr Robinson was clearly enraged.
Afterwards the DUP leader demanded an apology and retraction. This morning Tom Elliott will formally refuse to give one.
He advised Mr Robinson: “For goodness sake, you take the rough and the tumble in political debates.”
Last night Peter Weir, a candidate in North Down speaking on behalf of Mr Robinson, said that Mr Elliott “should do the mature thing and accept he got it wrong in the heat of debate”.
PETER ROBINSON (of Caitriona Ruane, Conor Murphy and two DUP ministers who he said had shown budgetary discipline): “All of them are having to contemplate things that they would never choose to, but I haven’t heard them whingeing and whining out in the community.” (Belfast Telegraph, February 16)
TOM ELLIOTT: “Even you, Peter — you said: ‘Oh, the Minister for Education's great!' (leaders’ debate, April 21)
PETER ROBINSON: “That is a lie, an absolute unmitigated lie ... a lie from Hell.” (leaders’ debate April 21)