Media playback is unsupported on your device Media caption David Cameron was questioned by Mary Hassan from County Londonderry and asked if he would consider entering a coalition with the DUP.

David Cameron has said he "will never validate" the Democratic Unionist Party's stance on lesbian, gay, bisexual, or transgender (LGBT) issues.

The Conservative Party leader added that he "profoundly disagreed" with DUP policy on the subject but refused to rule out a coalition with DUP MPs.

He made his remarks during Radio 1 Newsbeat's Live Lounge leader debate.

The DUP, which opposes gay marriage, said the party had already ruled out being part of a coalition government.

A DUP spokesman told the BBC the party was not seeking cabinet positions.

"In any case, redefining marriage is a matter for the Northern Ireland Assembly rather than Westminster. David Cameron also realises that a fair number of his Conservative MPs also voted against redefining marriage," the spokesman added.

Mr Cameron was questioned about his commitment to gay rights as he was grilled by 10 potential young voters in the Newsbeat debate.

Among the questioners was Mary Hassan, from Londonderry, Northern Ireland, who identifies as a member of the LGBT community.

Image caption David Cameron said he "profoundly disagreed" with DUP policy on lesbian, gay, bisexual, or transgender (LGBT) issues, but refused to rule out entering a coalition with the party

She accused the DUP of causing "significant and long-term damage" to lesbian, gay, bisexual, or transgender people in Northern Ireland.

Ms Hassan told Mr Cameron that the DUP had "voted consistently against government bills to prohibit discrimination on the basis of sexual orientation".

"They've consistently blocked motions for marriage equality and uphold a gay blood ban and currently are putting forward the conscience clause bill.

"Now, I'd like to know - is staying in office more important that the LGBT community in Northern Ireland?" Ms Hassan asked.

She challenged Mr Cameron to rule out forming a coalition government with the DUP in the event of a hung parliament after next month's general election, as a sign of solidarity with the LGBT community.

Mr Cameron said he was campaigning for a Conservative majority and had strong track record of promoting gay rights.

"I totally disagree with the DUP about this [LGBT] issue and nothing I ever do will go against the values I have about believing in equality and equal rights for gay and lesbian people and I've put that, as it were, on the line by supporting equal marriage.

"So I'm never going to change my views about that."