Lord David Trimble joined the Tories last year
The Conservatives will fight for every seat in the UK, including Northern Ireland, at the next General Election.
Former Ulster Unionist leader, Lord Trimble, made the announcement to delegates at the Conservative Party conference in Birmingham.
The Conservatives are currently engaged in discussions with the Ulster Unionists about a possible merger.
Lord Trimble told the conference he hoped the Conservatives would have the help of the UUP at the next election.
His comments come after Tory shadow secretary of state said there was no reason why MPs from NI could not be part of a cabinet, if his party were to merge with the UUP.
Owen Paterson was speaking ahead of the Conservative Party conference on Sunday.
He said MPs should be able to work on all levels at Westminster: "Why should Northern Ireland be different?"
"Why shouldn't Northern Ireland have politicians from here playing a full part in our national politics."
UUP leader Sir Reg Empey said a cabinet post for the Ulster Unionists was a possibility.
"The general principle would be that if you are part of a wider whole then you participate at all levels. That is the inevitable downstream consequence going forward," he said.
A report from a working group set up to examine whether there should be a merger between the Ulster Unionists and the Conservatives is due in the autumn.