Image copyright PA Image caption Northern Ireland is now the only part of the UK which has not passed a law to introduce same-sex marriage

Prime Minister David Cameron has told MPs that tolerance towards people of a different sexuality is an important part of being British.

Mr Cameron was responding to a question from the DUP's Gregory Campbell about the row involving the County Antrim bakery, Ashers.

The Christian-run bakery refused a customer's request to make a cake with a slogan supporting gay marriage.

Mr Campbell wants to see a conscience clause in equality legislation.

He raised the issue during Prime Minister's Questions in the House of Commons.

Mr Cameron responded that he was not familiar with the details of the case but thought tolerance towards those of a different sexuality was an important part of being British.

Ashers Baking Company had declined an order from a gay rights activist, asking for cake featuring the Sesame Street puppets, Bert and Ernie.

But it could face legal action from the Equality Commission for declining to make the cake, ordered for a civic event in Bangor Castle Town Hall, County Down, to mark International Day Against Homophobia and Transphobia.

The customer also wanted the cake to feature the logo of a Belfast-based campaign group called "Queerspace".

Speaking after PMQs on Wednesday, Mr Campbell, the East Londonderry MP, said: "There have been a number of cases across the United Kingdom where so-called equality legislation has impeded the ability of people to uphold their religious beliefs.

Media playback is unsupported on your device Media caption Gregory Campbell and David Cameron on Christian gay cake row

"This latest case locally has seen a family-owned bakery threatened by legal action because they would not print a political slogan onto a cake. Such a message ran contrary to the company's Christian values.

"It is disappointing that the prime minister would not comment on the need for religious freedom to be protected through the introduction of a conscience clause. "

He added: "Tolerance needs to be a two-way street, but this case highlights that currently those who cannot support a particular political campaign may find themselves forced before the courts. That is totally unacceptable."

Media playback is unsupported on your device Media caption The firm's general manager, Daniel McArthur, recorded a statement which the Christian Institute posted online

The bakery, which was founded in Newtownabbey in 1992, is run by the McArthur family.

The directors, who are Christians, operate six shops in Northern Ireland and employ 62 people.

The firm's 24-year-old general manager, Daniel McArthur, said marriage in Northern Ireland "still is defined as being a union between one man and one woman" and said his company was taking "a stand".

The customer placed the order in Ashers' Belfast branch a number of weeks ago, and it was then passed to their head office.

In an online statement, Mr McArthur said: "The directors and myself looked at it and considered it and thought that this order was at odds with our beliefs.

"It certainly was at odds with what the Bible teaches, and on the following Monday we rang the customer to let him know that we couldn't take his order."

Mr McArthur added: "I would like the outcome of this to be that, any Christians running a business could be allowed to follow their Christian beliefs and principles in the day-to-day running of their business and that they are allowed to make decisions based on that."