Same-sex partners could lose money by getting "married" when the Civil Partnership Bill comes into force.

Brighton and Hove Green city councillor Simon Williams has warned that many gay and lesbian couples may be unaware they will lose benefits as a "married" couple.

The new law, which comes into effect in December, will make it easier for same-sex couples to be assessed for benefits as joint partners.

Coun Williams said: "Many same-sex couples who have been living happily for years and claiming benefits as individuals could suddenly find themselves assessable as a couple for significant benefits. These include housing benefit and disability living allowance, whether or not they chose to register their partnership under the new system.

"Claimants will, for the first time, have their partner's income classed as theirs when calculating benefit entitlement."

He said some couples could be up to 40 per cent worse off if assessed as partners rather than individuals.

He said: "The Government needs to explain these issues to people. People are completely in the dark about what could be a drastic reduction in income for some same-sex couples."