An attempt to introduce domestic partnerships for gay couples is marriage by another name, pressure group Preserve Marriage said last night.

The organisation claimed that Minister of Home Affairs Walton Brown’s Bill to create legal recognition for same-sex couples would open the door to full marriage in the future.

Melvyn Bassett, chairman of Preserve Marriage, said: “To legislate against same-sex marriage and simultaneously introduce civil unions under the guise of a Domestic Partnership Bill is an introduction of a parallel form of marriage.”

He claimed: “The public is well aware that civil unions often give legal footing to the ‘separate but equal’ argument that has led to same-sex marriage rulings in the court in other jurisdictions.”

Dr Bassett said: “To avoid a future legal challenge to Minister Walton Brown’s 2017 Domestic Partnership Bill, an appropriate amendment could be made that would offer a provision of legal recognition and benefits to all non-married persons and can be applied to a variety of relationships.

“Such an amendment would grant legal authority and rights to a designated person or registrant which would include, but not require, an intimate relationship.”

Dr Bassett added: “The legislation under these circumstances would not be seen as parallel to the Marriage Act and would less likely be used as a basis to appeal to the courts for same-sex marriage.”

The group added that it was “pleased” that the Government was “moving forward with its commitment to uphold marriage as the union between a man and a woman”.

But Dr Bassett accused the ruling Progressive Labour Party of stealing the former One Bermuda Alliance government’s “rejected Civil Unions Bill” of last year and giving it a new title.

He claimed that the PLP had “campaigned on a platform to eliminate same-sex marriage”.

Dr Bassett added that it was “perplexing why the Government ... is now introducing same-sex marriage in a different format”.

Preserve Marriage conceded that by international human rights law, the Government “was obliged to provide same-sex couples with legal benefits”.

Dr Bassett said: “The Government can legislate these benefits and still maintain its election promise by amending the current Bill.”

The Supreme Court ruled in May that the island’s Registrar General could not reject a gay couple’s application to marry in Bermuda.

Puisne Judge Charles-Etta Simmons said that the common law definition of marriage as between a man and a woman was “inconsistent with the provisions of the Human Rights Act as they constitute deliberate different treatment on the basis of sexual orientation”.

The decision paved the way for same-sex marriage on the island.

The first same-sex couple made their vows at the Registry General’s office less than a month later.