The most senior Catholic in the British Government, Work and Pensions Secretary Iain Duncan Smith, has confirmed that he will be supporting Prime Minister David Cameron’s pledge to introduce equal civil marriage for gay and lesbian couples. In what appears to be an apparent remarkable evolution of his own personal approach to LGBT rights, he pointed out that in a country where so many heterosexual couples are breaking up, marriage equality is a positive method of creating a more stable society.

Mr Duncan Smith, a former leader of the Conservative Party, is considered by many to be the cheerleader of the socially conservative wing of the party. While leader of the party, he made it party policy to oppose gay couples being given equal rights to adopt children and opposed the repeal of Section 28, which more or less banned discussion of homosexuality within schools. This led to a rebellion by prominent liberal Tory MPs including former party chairman Francis Maude and former Defence Secretary Michael Portillo.

Following a leadership coup, Mr Duncan Smith was one of a number of high profile Christian Conservative MPs that voted against the Civil Partnership Act in 2004. His successors as Tory leader, Michael Howard and David Cameron supported legislation to give gay and lesbian couples almost the same rights as straight married couples. He and David Cameron also opposed equality in fertility rights for lesbian couples and in 2009 a think tank he founded argued that partners of gay parents should have less rights than the partners of straight parents.

In 2006, Mr Duncan Smith said: “When it comes to gay couples they don’t even register on the Richter scale of how to bring up kids. Men and women are the ones who have the children. Gay couples have nothing to do with this at all.”

In an interview with The Times today, Mr Duncan Smith confirmed that he would vote for the legislation in the House of Commons explaining: “I’m for things that are about stability. I think our biggest problem is actually with cohabiting parents breaking up at the rate they do — heterosexual cohabitees, not gay couples — because they’re the ones leaving the trail of devastation afterwards.”

Mr Duncan Smith told The Times, a newspaper that has been cheer-leading support of equal marriage in the press, that he hoped that the Government will introduce a bill to end the ban on gay marriage as soon as possible.

It is unclear if Mr Duncan Smith has been placed under pressure to support the measure.