Obama backs same-sex marriage

US President Barack Obama has said he believes same-sex couples should be allowed to get legally married.

The remarks on Wednesday marked a shift in his position on the issue that is likely to please his political base and upset conservative rivals.

"It is important for me to go ahead and affirm that I think same sex couples should be able to get married," Obama said in an interview with ABC News' Robin Roberts.

Obama's comments came days after Joe Biden, the US vice-president, and Arne Duncan, the education secretary, both made statements to the press in support of same-sex marriages.

Social conservatives and religious leaders condemned his remarks.

Meanwhile, the Obama campaign attacked Republican Mitt Romney, who restated his opposition to same-sex marriage, as out of touch on the issue.

Obama travelled to the West Coast on Thursday for fundraisers in Seattle and Los Angeles likely to raise millions.

One fundraiser, to be held at the home of George Clooney, is expected on its own to raise $15 million, partially from a general raffle offering members of the public the chance to meet the Hollywood actor.

In the wake of his interview with ABC News, gay advocates applauded Obama's remarks.

Human Rights Campaign President Joe Solmonese said that the president's comments would "inspire thousands more conversations around kitchen tables and in church pews".

But Cardinal Timothy Dolan, president of the US Conference of Catholic Bishops, labelled Obama's remarks "deeply saddening".

Obama says he has concluded that it is important for him to affirm that he thinks same-sex couples should be able to get married.

"But it's also the Golden Rule, you know -- treat others the way you would want to be treated" he said.

He says he came to the conclusion over the course of several years of talking to family and friends.

In a Gallup poll conducted between 3 and 6 May, 50% of Americans  said they backed same-sex marriage, while 48% said it should not be legalised.