The bitter rivalry between the DUP and TUV has intensified with Peter Robinson claiming votes for his arch-rival Jim Allister were "wasted".
The DUP boss also warned of a "disaster" if the unionist vote was shredded between the six pro-Union candidates, increasing the prospect – as a Belfast Telegraph/LucidTalk analysis concluded – of the SDLP's Alex Attwood snatching a seat along with Sinn Fein's Martina Anderson.
First Minister Mr Robinson said 5,400 votes for Mr Allister in the last Euro race had failed to transfer to other unionist candidates.
But Mr Allister – a former DUP MEP – rejected the charge, and accused Mr Robinson of increasing the prospect of nationalists taking two of the three seats. The TUV leader said the DUP's candidate Diane Dodds was "very glad" of 25,000 TUV transfers in 2009 which allowed her to take the third seat, behind the UUP's Jim Nicholson and Sinn Fein's Bairbre De Brun.
Launching his party's European and local government campaigns yesterday, Mr Robinson reiterated his warning that amount of unionist candidates would fragment the vote.
Clearly referring to Mr Allister, he said some candidates spoke about fellow unionists in such tones that their supporters would be loathe to transfer votes.
"In the last European election well over 5,000 unionist votes were wasted by voting for Jim Allister when, as was inevitable, he was eliminated. Those votes did not go to any other unionist party," the DUP leader told party activists and candidates in Belfast.
"The same is the case for every unionist party that proliferates the poll without the realistic prospect of success. Non-transferable votes always occur when a candidate is eliminated. Those are votes wasted to unionism. The multiplicity of unionist parties is damaging unionism.
"It would be a disaster if, as a result of a plethora of unionist candidates standing in the election, that our votes were shredded and unionism lost out on representation in Europe."
But Mr Allister argued: "The only way that the vote can be split in a PR election is if people do not transfer down the unionist ticket. TUV is making it clear in all our literature that after voting 1 TUV, our supporters should transfer to all other pro-Union candidates.
"Considering that in the last European election his candidate Mrs Dodds scraped in sub quota and was glad of 25,000 TUV transfers to get her elected to the third seat, Mr Robinson has no room to make demands on transfers.
"We are sure unionists will make up their own minds and, I suspect, many will be itching to pass verdict on his stewardship in Government with Sinn Fein.
"It is essential for unionism that parties put their personal feelings behind them when talking about transfers. To refuse to advocate transfers to other unionists is to declare a preference for a nationalist victory. Is this where Mr Robinson has got to?"
Mr Robinson and Mrs Dodds said the DUP wanted "radical change" in the EU, but stopped short of supporting withdrawal.
"I've vehemently resisted the federalist agenda of the Brussels establishment, being a constant voice for protecting our British national sovereignty," she said.
"The United Kingdom's relationship with Europe must change. That change can't be just tinkering at the edges. It must be substantial, it must be radical, or it simply will not do.
"We want a Europe of free trading, sovereign nations, not a federal Europe where control over our borders and laws is ceded to Brussels."