Armed forces chaplains are coming under pressure to allow same-sex weddings in military chapels.

No same-sex couples in the Army, Royal Navy and Royal Air Force have yet been married in a military chapel in spite of regulations making provision for such ceremonies being passed 18 months ago. The 'sending Churches' responsible for the provision of chaplains are opposed to same-sex marriage.

Labour MP Madeleine Moon tabled a written question to Armed Forces minister Penny Mordaunt asking how many military chapels are registered to conduct same-sex marriages.

Mordaunt, MP for Portsmouth and a Royal Navy reservist, replied: "The Ministry of Defence allows same-sex marriages in military chapels, but none of the sending Churches using the chapels currently allows same-sex marriages to be conducted there.

"I have asked the chaplaincies of the three services to advise me on how Parliament's sanction of same sex-marriages may be fully implemented."

Chaplains are qualified officers who have been ordained in one of the recognised churches and chosen to hold a commission in one of the three services, the Army, Royal Navy and RAF. They wear military uniforms and accompany their units wherever they go. They exercise leadership but do not command, fight or bear arms.

Many of the chaplains who serve the 190 chapels in the services are from the Church of England, one of several recognised sending Churches. They cannot be forced to celebrate gay marriages, in the military or anywhere else and nor can buildings consecrated to the Church of England be licensed for same-sex marriage.

There has been a stand-off between the services and the churches over the issue since the Marriage (Same Sex Couples Act) 2013 was passed and the special regulations came into force. The special "protection" in law means the Church of England is locked out of ever having to perform a gay marriage in one of its own buildings without new legislation and no Church of England minister is allowed to perform a same-sex marriage.

Chapels shared with other denominations can only host gay marriages if every denomination sharing the building agrees.

Besides the Church of England, chaplains are supplied by the Church of Scotland, the Roman Catholic, Methodist, Presbyterian, Baptist, United Reformed and Congregational churches. There are also chaplains of the Buddhist, Hindu, Muslim, Jewish and Sikh faiths.

The Defence Secretary would have to consult with the relevant faith or faiths before any military chapel could be licensed for same-sex marriage, and all the denominations and faiths that use the building would have to consent.

In addition, the chapel can not have been consecrated according to the rites of the Church of England.