Labour's deputy leader has distanced herself from claims that the party now backs tax breaks for marriage.

Speaking in the Commons, leader of the House Harriet Harman said that the government should support all couples and their children.

The comments came after chief secretary to the Treasury Andy Burnham had said in a weekend newspaper interview that there is a "moral case" for marriage, in an apparent reversal of the Labour position.

The party had attacked Conservative plans to reward marriage through the tax and benefits system, with the prime minister even quoting the Bible to make his case, during his Bournemouth conference speech.

But following changes to the inheritance tax threshold for married couples and civil partners, Burnham told the Daily Telegraph that marriage is "better for kids"

"It's not wrong that the tax system should recognise commitment and marriage," he argued.

During business questions on Thursday, Harman joked that Burnham had assured her "that he is not planning to become the House of Commons marriage guidance counsellor".

However she added that: "The government's position remains this. We recognise that families come in all shapes and sizes.

"We recognise that there is no government policy that can make men and women happy together in their marriage... meanwhile it is the job of government to get on and support families with children and families with older relatives."

Gordon Brown had backed Burnham during prime minister's questions earlier in the week.

Acting Lib Dem leader Vince Cable had asked him why the tax system should "discriminate against millions of unmarried couples and their children".

Brown replied that: "It is because we recognise marriage in the tax system that we have made the changes that we have on inheritance tax...

"But as far as children's tax credits and child benefit are concerned, I believe that the duty of every citizen of this country is to support not just some children in our country, but all children."