The Conservative leader will be the guest speaker and star attraction at the event in the Ramada Hotel, on Saturday, December 6.

He will officially launch his party’s new pact with the UUP.

It has created a Joint Conservative and Ulster Unionist Committee which bridges the parties and will coordinate joint policies and manifesto pledges.

The new pairing will also field jointly selected candidates in European and Westminster elections.

Mr Cameron has been speculated to come to the conference. But it was just yesterday he confirmed: “I am delighted to be attending next week.

“The agreement between the Conservatives and the UUP will give all the people of Northern Ireland a new choice in politics.

“My attendance proves my commitment to this new political force, one that will allow everyone in Northern Ireland to participate fully in political life both in Northern Ireland and throughout the UK.”

Ulster Unionist leader Sir Reg Empey said: “David Cameron attending and addressing our conference is a very clear signal that the relationship between our parties is improving and that the campaign to promote a UK-wide pro-Union philosophy is gathering pace.”

Shadow secretary of state for Northern Ireland Owen Paterson said: “This proves how important the agreement is to both parties. This new political force will give real influence to all Northern Ireland voters on the crucial day-to-day issues such as taxation and the economy.”

The Ulster Young Unionist Council has also endorsed the moves the UUP has taken to adopt further links with the Conservative Party, labelling it as a “massive step forward” for Northern Irish politics.

Michael Shilliday, chairman of the Young Unionists, said: “When we look at the talks between the two parties we see something stronger than just electoral pacts; we see unionism becoming stronger across the United Kingdom. The young members of the party realise they are part of something truly historic.”

Commenting on the possible benefits these links may bring, Mr Shilliday said: “It is a reality that Northern Ireland’s 18 MPs have very little practical influence at Westminster. Rarely do our votes have much significance on a national level, with rare exceptions such as the 42-day detention, but even then only with the smell of raw opportunism from the DUP.

“Our decision will change that situation after the next General Election. Ulster Unionist MPs will take the Conservative Whip and will become full members of the Conservative parliamentary team. This will mean potentially, that we will be a part of the next British Government.”