A spokesman for Gordon Brown has exclusively explained to PinkNews.co.uk why the Labour MP and former PM was not present in the Commons for this week’s vote of the Marriage (Same Sex Couples Bill).

On Tuesday, 22 Labour MPs voted against the bill – and 16 MPs including Gordon Brown were not present for the vote.

In response, a spokesman for the former prime minister told PinkNews.co.uk: “Mr Brown had a planned trip to the United States in his capacity as UN Special Envoy for Global Education to promote and further his work towards universal global education. Unfortunately, the trip was arranged before the date of the vote was known and it was not possible to reschedule. He is fully supportive of the legislation.”

In 2010, before the general election, Gordon Brown told PinkNews.co.uk that he would not support same-sex marriage, writing in a readers’ question and answer feature, he said: “At the moment there’s a distinction drawn between civil and religious unions, and when civil partnerships were being introduced they took the same form as a civil union which a heterosexual couple would have. We later made it illegal to discriminate on partnership status – so it is illegal to treat someone in a civil partnership different to a married person.”

Mr Brown added: “That makes no practical difference in terms of rights and responsibilities, but does recognise that religious groups have the right to a certain degree of self-organisation on questions that are theologically important to them, including on the question of religiously-sanctioned marriage. So the provision of ‘marriage’ as opposed to the provision of same-sex or heterosexual civil unions, is intimately bound up with questions of religious freedom.”

At the time, Liberal Democrat leader Nick Clegg told PinkNews.co.uk that he supported same-sex marriage, while David Cameron said he was “open” to introducing marriage equality.

Ahead of Tuesday’s vote, Gordon Brown wrote on his website.

I am proud that our Labour Government was one of the first in the world to make civil partnerships legal.

I am also pleased that while I was at the Treasury we ended centuries of discrimination, providing equal financial rights for gay and lesbian couples, laws that ensured the same rights for all in the transfer of pensions and in inheritance. While Prime Minister our government agreed to end another discrimination: extending fertility rights to all women irrespective of sexuality.

I am pleased that the vast majority of the British public supported these progressive reforms.

I understand the strong feelings in the current debate but I take the view that it is now timely to agree to end another source of discrimination by legalising the right to marriage and I will support the legislation in the UK Parliament and when it comes to the Scottish Parliament.