The UK’s High Court will hear a legal challenge this week from a straight couple who want a civil partnership.

Civil partnerships, introduced by Tony Blair’s Labour government in 2005, allowed same-sex couples to register their unions through a system separate from marriage.

Though same-sex marriage was eventually introduced in 2014, civil partnerships available for same-sex couples only – and one couple is heading to the courts to change the law.

The government decided against opening up the system to straight people after a consultation found little interest, but London-based couple Charles Keidan and Rebecca Steinfeld will this launch a bid for judicial review at the High Court.

The pair’s case is set to be heard by justices on Tuesday and Wednesday, as they argue they should have the same rights as same-sex couple would.

The pair said: “We are taking this case because the UK Government is barring us, and many thousands of opposite-sex couples like us, from the choice of forming a civil partnership, and we want this to change.

“Personally, we wish to form a civil partnership because that captures the essence of our relationship and values.

“Civil partnerships are a modern social institution conferring almost identical legal rights and responsibilities as marriage, but without its historical baggage, gendered provisions and social expectations.

“We don’t think there is any justification for stopping us or other opposite-sex couples from forming civil partnerships.”

The pair contend that Section 1 of the Civil Partnership Act 2004, which restricts civil partnerships to same-sex couples, is incompatible with Article 14 (read with Article 8) of the European Convention on Human Rights, which states that everyone should be treated equally by law, regardless of sex or sexual orientation.

The case has attracted mixed responses from LGBT rights activists.

While veteran campaigner Peter Tatchell is among those to vocally support opening the system up to opposite-sex couples, others are in favour of letting interest in the system decline naturally.

Only a handful of same-sex couples have opted to have civil partnerships since marriages were opened up, putting the system’s long-term future in doubt.