Alex Kane has also raised doubt that an electoral pact with the DUP would actually benefit unionism as a whole.

The UUP strategist, who recently oversaw the party's internal review, last night told South Down Ulster Unionist Constituency Association that he was sceptical of recent overtures from DUP leader Peter Robinson on the subject of cooperation.

"I really do doubt the DUP's motives on this subject," he said.

"So much so, in fact, that I am tempted to borrow Mr Paisley's watchwords of 'never, never, never'."

Mr Kane said he believed that rather than worrying about unionist divisions, Mr Robinson "has made a calculation that a deal with the UUP would counterbalance the DUP's expected losses from the TUV (Traditional Unionist Voice)".

He added: "The DUP is going to have real problems as the recession begins to bite and Sinn Fein demands progress on those issues it put back on the agenda at Downing Street meetings last week.

"Again, I suspect that Mr Robinson would regard a pact with the UUP as something that would ease the pressures from those problems and provide some cover for him."

The DUP leader has spoken of the need to increase unionist turnout and also to look at potential pacts in areas like the Westminster seats of Fermanagh/South Tyrone and South Belfast.

He has even addressed the prospect that there could one day be a single unionist party.

UUP leader Sir Reg Empey has dismissed this idea.

He has also accused the DUP of stunts and PR, in suggesting talks through the media. But he is open to discussion on matters of mutual benefit and of benefit to unionism.

But Mr Kane said: "Even if the DUP and UUP did a deal isn't it possible that the SDLP and Sinn Fein would take action of their own and reach pacts in places like South Belfast and Fermanagh/South Tyrone?" – thus increasing the nationalist vote.

He also said that over the past year the UUP has overhauled its structures "and turned itself into a more efficient machine" and had no need to do deals with the DUP.

"In my own view the best way of increasing and maximising the pro-Union vote is for the DUP and UUP to do their own thing," he told the UUP audience.

"There is room in Northern Ireland for two mainstream pro-Union parties and it is dangerously absurd to believe that a pact or merger would lead to something better – it wouldn't.

"There is an untapped constituency out there, with a very substantial number of non-voters. So rather than limiting both our options and fishing from a diminishing pool we should have the courage, confidence and common sense to knock more doors and win over a new generation."

He added: "Yes, it is important that we maximise the total number of unionist seats in Westminster, the Assembly and local government. But we must not allow a situation in which the UUP is suckered into an arrangement that seems to be for the DUP's benefit."