One of Britain’s leading experts in family law has said that gay couples may soon be able to successfully use human rights laws to challenge the UK gay marriage ban.

Baroness Deech, who is the chair of the Bar Standards Board, is to deliver a lecture on civil partnerships and marriage at Gresham College, London, today.

The Daily Telegraph reports she will say that although two previous attempts to win the right to marry through the Human Rights Act failed, change in attitudes could mean similar appeals now will be successful.

Lady Deech will say: “In the passage of the few years since this judgment, it is possible that societal views have shifted sufficiently so that an appeal on the same grounds might have a different outcome.”

Civil partnerships grant gay couples almost all the rights of marriage.

Gay couples cannot have their ceremonies in church, although the government has been asked to consider allowing faiths the option of holding them. Heterosexual couples may not have a civil partnership.

Last month, PinkNews.co.uk reported that a straight couple in London, Katherine Doyle and Tom Freeman, were seeking gay and straight couples to launch a legal challenge at the European Court of Human Rights against the restrictions on marriage and civil partnerships.

Lady Deech will also criticise fertility rights for lesbians, saying that allowing female couples the right to have both of their names on birth certificates is “disguising true facts”.

She will say: “This is not a moral issue; it is about disguising true facts, and it is about confusing biological parenthood, legal and social parenthood.

“I regret the downgrading of the father as a person of importance – the legislative dismissal of the contribution of half the population to the upbringing of the next generation.”

She will conclude: “The limit to same-sex relationships is that they cannot be a reproductive unit in a way that is best for the welfare of the child if they cut out all contact with members of the other sex or falsify the birth registration. Tolerance of both types of parenting has to be ensured.”

Last month, Lady Deech called for a return to the Elizabethan ‘Poor Law’ which forced children to care for their adult parents. She has also attacked divorce laws which reward “gold-digger” wives.

In 2008, she tabled an amendment to the Human Fertilisation and Embryology Bill to retain the “need for a father”, but this was defeated by 164 to 93.