A straight British couple who reject marriage but want to seal their love with a civil partnership were told on Tuesday they could not because they are not gay.

Tom Freeman and Katherine Doyle, both 25-year-old civil servants, were turned away from Islington Registry Office in north London because the law says civil partnerships - introduced in Britain in 2005 - are only for same-sex couples.

Undeterred, the couple said they will take their fight for equality to court.

"We want to secure official status for our relationship in a way that supports the call for complete equality and is free of the negative connotations of marriage," Mr Freeman said.

"If we cannot have a civil partnership, we will not get married."

A spokesman for Islington Council said: "The law dictates that a civil partnership is only for couples of the same sex. The council must follow the law."

There are a small number of differences between a marriage and a civil partnership, including that a marriage can be conducted in a church, while a civil partnership cannot.

AFP