One of Britain’s leading family lawyers has accused David Cameron’s government of “faffing around with gay marriage” rather than tackling other injustices within marital law.

Lady Butler-Sloss, who retired as president of the Family Division of the High Court in 2005, said that the coalition government’s plans to legalise equal marriage went “attacked marriage”, the principles of which had been around for “millennia”.

In the first time the Baroness has spoken on the subject, she said legalising equal marriage would not give gay couples any significant new benefits, but would lead to the destruction of the definition of marriage.

The lawyer claimed that clauses which remove the concept of adultery in divorces of same-sex couples would lead to “immorality”.

During her time as a judge, Lady Butler-Sloss supported gay adoption, and as an independent peer she supported a Lords amendment to lift the ban on same-sex couples celebrating civil partnerships in religious buildings.

She went on to say, however, that new plans for equal marriage, and the plans by the coalition government were a “step too far”.

Despite her opposition to equal marriage, she maintained that she was not homophobic. She said: “I have always spoken in favour of gay relationships and the rights of gay people,” she said. “This does seem to me a different issue and one which attacks marriage.”

She said that she spoke partly out of her own Christianity, but that her stance on the issue went beyond religion.

“I think it is a destruction of the word ‘marriage’, which has been understood for many years to mean what the Christians say it does.

“It would not only affect Christians but it would affect Muslims, Jews, Hindus, Sikhs and all the other religions”, she continued.

She said that all major religions had historically seen marriage as being based on procreation.

No new rights would be given to same-sex couples by the introduction of equal marriage, she said, but went on to say that she thought there were more important issues which could be addressed by the government.

She said that there was an urgent need for a new look at the law in order to prevent unmarried mothers being left with no home, income or rights if they are left by their partners, which she said was “profoundly unfair”.

“[I cannot understand] why the Government is faffing around with gay marriage when they need to be righting a wrong,” she said.

She went on to say that that Marriage (same sex couples) Bill could lead to “immorality” because there was no official line on what constituted sex between same sex couples, reports the Telegraph.

Speaking on the US Supreme Court hearings around equal marriage this week, television satirist Jon Stewart criticised the justices for deliberating over whether procreation was important in order to define the meaning of marriage.