A heterosexual couple who object to the "patriarchal baggage" of marriage have lost their latest battle for the right to enter into a civil partnership.

Rebecca Steinfeld, 35, and Charles Keidan, 40, want to secure legal recognition of their seven-year relationship through that route - but are prevented because the Civil Partnership Act 2004 says that only same-sex couples are eligible.

The academics, who live in Hammersmith, west London, and have a 20-month-old daughter, say that the Government's position is "incompatible with equality law" .

In November, they challenged High Court judge Mrs Justice Andrews's decision to dismiss their judicial review action.

But on Tuesday, the Court of Appeal dismissed their challenge.

Karon Monaghan QC told Lady Justice Arden, Lord Justice Beatson and Lord Justice Briggs that the issue was whether the bar on opposite-sex couples entering into civil partnerships was incompatible with Article 14 of the European Convention, which relates to discrimination, taken with Article 8, which refers to respect for private and family life.

She said: "They wish very much - and it is of very considerable importance to them - to enter into a legally regulated relationship which does not carry with it patriarchal baggage, which many consider comes with the institution of marriage."

Dan Squires QC for the Secretary of State for Education, who has responsibility for equalities within Government, said that a decision was taken, after two public consultations and debate in Parliament, not at this stage to extend civil partnerships to opposite-sex couples, abolish them or phase them out.

It was decided to see how extending marriage to same-sex couples impacted on civil partnerships before making a final decision which - if reversed in a few years' time - would be disruptive, unnecessary and extremely expensive.

He described the judge's decision as "unimpeachable".

The judges agreed the couple had established a potential violation of Article 14 of the Convention, taken with Article 8 but Lady Justice Arden dissented on the question of whether the policy of "wait and evaluate" was justified at present.

Ms Steinfeld said: "We are pleased that today's ruling has shown that the Government must act very soon to end this unfair situation.

"All three judges agreed that we're being treated differently because of our sexual orientation, and that this impacts our private and family life.

"All three rejected the argument that we could 'just get married'. All three emphasised that the Government cannot maintain the status quo for much longer - they are on borrowed time."

Ms Steinfeld said Lady Justice Arden accepted their case on almost every point.

"We lost on a technicality, that the Government should be allowed a little more time to make a decision.

"So there's everything to fight for, and much in the ruling that gives us reason to be positive and keep going."

Mr Keidan said: "The Court of Appeal has made it clear the status quo cannot continue.

"The Government should now recognise the benefits of opening civil partnerships to mixed-sex couples.

"The measure is fair, popular, good for families and children, and long overdue. They have everything to gain."