The DUP has been challenged to state publicly that its Westminster candidates who are also MLAs will not 'double job' if elected as MPs.
The gauntlet was thrown by the party's arch-rival, Jim Allister, who pointed out that incumbent East Antrim MP Sammy Wilson and East Londonderry MP Gregory Campbell are also Assembly members.
The Traditional Unionist Voice leader said that given how past DUP manifesto had pledged to end double jobbing, MLA candidates such as Jonathan Bell in South Belfast and Alex Easton in North Down should make their position clear.
Speaking at his manifesto launch in Templepatrick, Mr Allister said Mr Wilson and Mr Campbell "seem to think it is enough to turn up on Wednesdays" at Westminster.
And he claimed Mr Wilson had missed two-thirds of the votes in the last Parliament. He said before the last general election in 2010 - when Mr Robinson lost his East Belfast seat - all except the party leader had promised to give up their second seats.
"The East Belfast electorate took care of the first issue but two other MPs brazenly defied their solemn commitments and have continued double jobbing and seem to be prepared to stretch it to the very end," he said.
The TUV chief said the DUP had "over-hyped" its likely role in the negotiations to form a Government if a hung parliament emerges after the May 7 poll.
"If you are going to have an influence you have to actually be there," he said.
Mr Allister also accused DUP leader Peter Robinson and Ulster Unionist boss Mike Nesbitt of being "disingenuous" over the 'graduated response' strategy to the north Belfast parades impasse which lead to a loyalist protest camp at Twaddell.
But the North Antrim MLA denied he had been led up the garden path over the parades protest and the Unionist Forum.
"It was necessary to test that... but I don't think that (Mr Robinson and Mr Nesbitt) were genuinely committed... and pretended they were going to embark on a graduated response which would have meant an ever-tightening pressure," he said.
The TUV manifesto, entitled The Real Alternative, said there should be no further devolution of powers to Stormont - and warned about the impact of corporation tax powers on Northern Ireland's block grant.
And it argued: "We have a system of government which shackles us to the bankrupt Republic by way of multiple north/south bodies, while we fail to exploit the advantages of being part of one of the world's biggest economies as part of the UK."
Mr Allister said his party was "building its base" in this election in preparation for potential gains in next year's Assembly election following its local government performance last year, when it gained 13 seats.