Most Britons back same-sex marriage legislation with only a third against.
That's the result of a new poll by YouGov.
It indicated ongoing support for the legislation going through the UK Parliament for the change in England and Wales. Separate legislation is being developed in Scotland.
The survey found 54% of Britons support same sex marriage legislation, with 36% opposed. Among Conservatives, more people oppose the measures than support them but the margin is narrow (48% to 45%).
And 64% of Britons support opening up civil partnerships to straight couples. Heterosexuals in a relationship were the most likely to back the change (73% supportive).
Civil partnerships give couples similar legal rights as civil marriage and have been available to same sex couples since 2005. At present, straight couples cannot have a civil partnership.
The poll also looked at whether people preferred marriage or a civil partnership. Nearly three-quarters of Britons (74%) would prefer to be married to someone 'in an ideal world'. Only one in 20 (5%) would prefer a civil partnership.
This shows why it is important to allow same sex couples to marry – most Britons still see marriage as the ideal, preferring marriage to a civil partnership.
The Marriage (Same-Sex Couples) Bill is scheduled to have its report stage and third reading today and tomorrow (20 and 21 May).
Conservative MP Tim Loughton has tabled an amendment that would open up civil partnerships to straight couples.
The idea of straight civil partnership is scheduled for review in 2019 but Loughton has said the government cannot wait that long to fix the 'glaring inequality' that same sex couples will be able to choose between a marriage and a civil partnership whereas straight couples can only marry.
But his amendment is seen by some as an attempt to wreck the bill.
David Cameron has now stated that he will look at making civil partnerships available to all couples. Government ministers have claimed opening civil partnerships up to straight couples would cost £4 billion ($6 billion €4.7 billion) and delay same-sex marriages for up to two years.
The Marriage (Same Sex Couples) Bill passed the House of Commons on 5 February 2013 with 400 votes to 175, a move Cameron called 'an important step forward'. But it still has to pass this hurdle and move through the House of Lords before it can become law.