A proposal to add mothers’ names to marriage certificates has been rejected for excluding gay couples.

The proposal had intended to include mothers’ names on marriage certificates, in a bid to “reflect modern Britain”.

The certificates currently only ask for the name of each spouse’s father. The new proposals are intended to include mothers on equal footing to fathers.

However the Home Office has rejected the plans, saying it could not agree to them as assuming that couples have opposite-sex parents is exclusionary.

Prime Minister David Cameron had planned to make the change, saying only including a father’s name “does not reflect modern Britain”.

The new law would mean marriage certificates up and down the country would be exchanged for ones which allow for a mother and a father’s name.

Campaigners for the change, who had raised tens of thousands of signatures have said the rejection of the plans constitutes “political correctness defying commonsense”.

A Bill will be debated in Parliament next month would make changes to the Marriage Act 1949 and the Civil Partnership Act 2004.

It would “make provision for the recording of the name and occupation of the mother of each party to a marriage or civil partnership for registration purposes”.

Labour MP Christina Rees, who proposed the legislation, said: “It is safe to extrapolate that hundreds of thousands of marriages have taken place while the Government failed to act.

“That is hundreds of thousands of instances in which women have been accorded second-class status. In a developed country in the 21st century that beggars belief.”

Another MP who also supports the campaign to have the change made, said: “On behalf of ordinary, average, not brilliant, fantastic mothers everywhere, I want to say that sometimes our children love us too and might want us on their marriage certificates, along with their fathers.”

Home Office Minister Richard Harrington said the Government could not agree with the proposed change as they did not incorporate those with “different family circumstances”.

He said the Bill “does not reform the whole registration process. It would simply require the replacement of tens of thousands of books at a cost of £3 million.

“The Bill does not take account of different family circumstances, where there may not be a mother and father.

“Members have mentioned many particular cases relating to that. It also does not give flexibility for the future.

“After we have amended the law, the matter may not be again for another 100 or 200 years, so we have to get things right.”

The Telegraph reports that Home Office sources specifically noted same-sex couples as an example.

The director of the adamantly anti-gay marriage group the Coalition for Marriage, Colin Hart criticised the rejection.

He said: “For most ordinary people naming the mother and father on a marriage certificate is an obvious thing to do and they could see no reason why the whole proposal should be vetoed because of a tiny proportion of children born into other relationships.

“This is political correctness defying commonsense. This is a small change but one which makes a huge difference to a large number of people and it is being denied because of concerns about offending people in a same sex marriage.”

Mr Hart suggested that same-sex couples could be made to sign a different document.