Democratic Unionist Party leader Peter Robinson and Sir Reg Empey, head of the Ulster Unionist Party, were involved in a meeting at the headquarters of the institution in Belfast at the beginning of last month.

A spokesman for the Orange Order said: "It was a private meeting to discuss Unionist unity which is a long term aspiration of the Orange Order."

The Order's Grand Master Robert Saulters and secretary Drew Nelson hosted the discussions which took place before Mr Robinson temporarily stood down as the Northern Ireland First Minister in the aftermath of the sex and money scandal involving his disgraced MP wife Iris.

The Conservative Party's Northern Ireland spokesman Owen Patterson organised secret talks in the greater London area between the two parties.

Senior members of both sides believe there will have to be some sort of electoral pact in advance of this year's general election in a bid to win back seats in south Belfast and Fermanagh-south Tyrone.

But, more importantly, they fear Sinn Fein could be returned as the largest single party at the next Northern Ireland Assembly election leaving Martin McGuinness as potentially the next First Minister at Stormont unless they can come to an agreement to prevent splits in the Unionist vote.

That election is not due until next year, but that poll might be called if crucial talks between the DUP and Sinn Fein fail to agree a date on the transfer of policing and justice powers.

Mr Robinson and Sir Reg are already under pressure from the emerging threat of Jim Allisters smaller Traditional Unionist Voice (TUV) which is vehemently opposed to the powersharing executive.

Ulster Unionist MLA David McNarry, who took part in the talks with the Orange Order, said if the policies were not right, then the two parties could not come together. But he also told BBC Northern Ireland's Hearts and Minds political affairs programme: "United we stand, divided we fall.....There cannot be three Unionist parties, that's for sure, to shred the vote.