The Isle of Man has approved a bill to legalise gay marriage.

The island in the Irish Sea is not officially part of the United Kingdom but is a ‘crown dependency’ which is responsible for its own laws. Its parliament, the ‘High Court of Tynwald’, is made up of two chambers: the elected House of Keys and the indirectly chosen Legislative Council. The term ‘key’ is thought to derive from the Manx language term ‘kiare as feed’, 24, a reference to the number of members in the House.

This week, the Legislative Council approved the Marriage and Civil Partnership (Amendment) Bill which grants full marriage rights to gay couples. The measure was passed by six votes to three on its third reading, after members of the House of Keys passed it last month. It will become law once it receives Royal Assent.

This marks a huge change on the island which introduced civil partnerships in 2011 after only legalising homosexuality in 1992. Gay rights campaign group the Manx Rainbow Foundation welcomed the passage of the bill and said it represented the island “shaking off its dark past”.

The Isle of Man’s openly gay Chief Minister Alan Bell said that the people on the island’s response to the gay marriage referendum in Ireland was “quite heartening” as he had “not heard a single negative reaction to it”. The situation “helped to clarify [his] thoughts” on the issue of marriage equality.

It is “a totally logical human right and human expectation that straight couples and gay couples should be able to enjoy life with the partner that they choose”, he added.

Once the bill receives Royal Assent, the only part of both the British Isles and the United Kingdom which does not have marriage equality is Northern Ireland.