Jim Allister has challenged the DUP to make clear if they would take the position of Deputy First Minister if Martin McGuinness took the top post.
DUP leader Arlene Foster has warned that just a small swing of votes could result in the Sinn Fein veteran becoming First Minister.
But while the prospect of Sinn Fein becoming the largest party is a long shot, TUV leader Mr Allister said the DUP could thwart their own "nightmare scenario" by simply refusing to nominate a deputy - although it would mean Stormont would collapse.
"Do you think I would shed any tears over that?" Mr Allister told the launch of his party's manifesto for the Assembly elections yesterday.
As the election battle on the unionist side heats up, Mr Allister also accused his former DUP colleagues of "hypocrisy" after agreeing the 'Fresh Start' deal with Sinn Fein - despite Provisional IRA involvement in the murder of Kevin McGuigan in Belfast last year.
And he said Mrs Foster had now agreed to the same arrangement with Sinn Fein over which she left the Ulster Unionist Party in 2003 amid a row over "guns and government".
An independent panel set up by the Government in the wake of the murder concluded that the structures of PIRA remain in existence "in a much reduced form".
And it added: "PIRA members believe that the Provisional Army Council oversees both the PIRA and Sinn Fein with an overarching strategy."
Mr Allister said yesterday after their "one day in, one day out" protest by DUP ministers, the DUP had agreed to "sweep murder under the carpet in order to cling to office".
The TUV manifesto said despite the panel's conclusions "amazingly the DUP response was to renew their government vows with Sinn Fein".
"What a shameless climbdown! Guns and government, as with (former UUP leader, Lord) Trimble now don't matter to the DUP.
"Ironically it was over that very issue that Arlene Foster resigned from the UUP. Now she leads the DUP in precisely that arrangement."
The DUP hit back, accusing Mr Allister (below) of wanting to wreck Stormont and offering no achievable way forward.
North Down candidate Peter Weir said: "Arlene is going into the election to win it. Jim Allister wants to wreck Stormont. He wants to take us backwards. Arlene has a five-point plan for Northern Ireland.
"It deals with jobs, health, education, infrastructure and family budgets.
"To implement this plan, Arlene Foster needs as many MLAs returned to Stormont as possible."
And he added: "More MLAs means more influence and more ministers. Jim attacks fellow unionists but offers no achievable way forward." The TUV is hoping to build on its success in the last local government elections, when it won 13 council seats, and is fielding 15 candidates for the Assembly contest.
Insiders admit the party's best prospect may be in South Down where their standard-bearer is former Ukip councillor Henry Reilly.
But given a strong enough performance in his North Antrim stronghold, Mr Allister could bring Timothy Gaston in with him on transfers.
Mr Allister argued the TUV has proved the "catalyst for change" at Stormont, with other parties - the Ulster Unionists and SDLP in particular - now considering going into opposition after the May poll.
But he said the dysfunctional, mandatory coalition system in the Assembly "will never be capable of working" without root and branch change, leading to a voluntary government.
"We will urge people to pass their verdict on the excruciating failure of the last five years when that which passes for government has lurched from crisis to crisis," he told the event in south Belfast.
"This system of government will never work, it doesn't matter how many 'fresh starts' it proclaims of itself, because it defies the basic rules of democracy and the basic matters which are afforded across the world in democratic states."