Plans for humanist weddings and pension rights for those in same-sex marriages will feature in this afternoon’s House of Lords debate of the Marriage (Same Sex Couples) Bill.

As part of the committee stage, peers will continue the process of scrutinising the legislation.

An amendment for humanist weddings was withdrawn in the Commons last month.

Attorney General Dominic Grieve warned that it would fall foul of the European Convention on Human Rights (ECHR) as any “belief organisation” would be able to claim they were being discriminated against if they weren’t able to perform marriages.

Mr Grieve said: “I am highlighting that there is a serious defect in the amendment that has been presented to this House, because it would have the consequence – which I think is quite obvious when you look at it – that because of the discriminatory nature of the favour it gives to humanists, as opposed to other secular organisations, that it would have the consequence of making it incompatible with the [ECHR] rights.”

At the moment, anyone taking part in a humanist ceremony in England and Wales must still have their marriage made legal through a register office.

However, Humanist ceremonies have been a fully legal form of marriage in Scotland since 2005.

Writing for the Labour Lords website, Baroness Thornton, Labour’s Shadow Equalities Minister in the Lords said: “I have been a humanist all my life, and it seems very unfair that if either of my children had wished to have been married at a Humanist wedding service they would have to go to Scotland, Sweden, the US or Australia.

“To be married at home however, they would have had to have a civic ceremony followed by a humanist ceremony, with the spirituality and commitment that marriage ceremonies encompass to make it the most special day.”

She added: “It strikes me that the Coalition government’s red tape challenge and its stated commitments to both competition and equality should lead us to conclude that this area is one where there is an injustice and unfairness in need of a remedy. So I hope today we get a positive response from ministers. And bearing in mind it is 19 years since the last marriage bill, one can’t blame Humanists for thinking it unreasonable to have to wait another 19 before this anachronism is addressed.”

Pension rights for those in same-sex marriages will also be discussed by peers.

In May, Conservative MP Mike Freer criticised the same-sex marriage bill for failing to address pension inequalities and tabled an amendment. 

The bill in its current form will allow pension providers to discriminate against gay married couples as well as those in civil partnerships, by ensuring they receive far less survivor benefits than their straight counterparts.