The Ulster Unionist's alignment with the Tories has effectively ensured that the recent period of British neutrality in Ulster will be at an end if David Cameron becomes prime minister.

YOUR VIEWS: Will the UUP-Tory electoral pact benefit unionism?

While the pact between the two parties is focused on providing a new non-sectarian alternative in local politics, and the Conservatives are also noting that the constitutional issue is settled, the years of "no strategic or economic interest" in the Province, which emerged under Margaret Thatcher, are over.

Sir Reg said: "For years, John Hume and others had convinced British governments to be neutral in Northern Ireland. But any government in Dublin is never neutral, given that the parties that make it up are of a nationalist persuasion.

"What we now have with the Conservatives is a party which may well form the next British Government and is no longer neutral in terms of the Union.

"Just recently Martin McGuinness made a statement saying that unionists would never have any power unless they worked with them (Sinn Fein).

"But when this (Tory deal) rolls out, people will have an opportunity to vote for candidates at elections who are very likely to form the next British Government and will have real power in decisions over taxes and fuel duties and influence over interest rates and the overall economy.

"And while I am 100 per cent supportive of devolution, I am also 100 per cent supportive of our place in the United Kingdom and that side of our constitution. This link with the Conservatives means we can have our cake and eat it if you like – by being involved in both governments that matter to our region.

"We will have a product to offer Northern Ireland people which no one else will have. And David Cameron has made it clear that, subject to individuals' abilities, he wishes to appoint local or regional members of his Cabinet."

Sir Reg Empey admitted he was taken aback by the overwhelming way in which his party's ruling executive endorsed a new pact with the Tories – with not one vote against it.

Aside from one abstention, at a decision meeting on Thursday evening, the Ulster Unionists wholeheartedly decided to venture into the new alignment which could redefine local politics.

Sir Reg said one of the attractions for members was that the arrangement is "purely voluntary" – not based on any constitutional or legal change to the UUP or Tories – and if it does not work out either side can withdraw at anytime.

It is also an equal partnership in terms of the Joint Committee which will have four members from each party sitting on it – with equal status and decisions agreed by consensus.

Identification of the members of the committee is the next step in the evolution of the new partnership.