A Liberal Democrat member of parliament has put forward two amendments to the Marriage (Same Sex Couples) bill.
After the House of Commons voted overwhelmingly in favor of the bill by 400-175, it now goes onto a committee stage.
While only 19 MPs are in the committee, others can put forward suggestions.
Julian Huppert, the Lib Dem MP for Cambridge, is supporting opening up civil partnerships for straight people, and allowing humanist weddings in England and Wales.
Speaking to Gay Star News, he said: ‘I think we should avoid discrimination, and therefore ensure that couples are not prevented from having either a wedding or a civil partnership just because of their gender.
‘There are opposite-sex couples who don’t want to get married but would like to have their relationship officially recognized in a civil partnership.
He continued: ‘My other amendments are specifically designed to allow humanist weddings in England and Wales. These are extremely popular in Scotland but are not allowed in the rest of the UK – there has to be a civil wedding, to which a humanist event can be appended.
‘Couples choose a humanist wedding because they want a ceremony that is built around them and their lives and values together.’
The 34-year-old MP said if the law is to be fair, the government should welcome allow straight couples to have a civil partnership.
Richard Lane from Britain's largest gay charity Stonewall expects no major hiccups in the committee stage, but is wary of it becoming a 'Christmas tree bill', where MPs involved can hang their own, often unrelated or amendments on the bill.
For Lane there could be a risk of the committee process straying from the 'core issue' of giving equal rights to same-sex couples.
Speaking to GSN, he said: 'Some groups may undermine the point of giving protection for LGBT people.
'Things like the humanist weddings I think may be a red herring. Changes people want to make should not be done at the expense of what we're trying to achieve.’
However Huppert does not see it that way, saying he wants to ensure the wording is right for the bill.
‘That’s why I have put forward my amendments, to make sure this bill is very relevant to the relationships we are seeing today,’ he said.
The bill to legalize marriage equality in England and Wales has now reached the committee stage, where 19 MPs will decide behind closed doors if they should edit or change aspects.
It will be brought to a conclusion on 12 March.