The Ministry of Defence is investigating claims made by the Conservative MP Sir Gerald Howarth that military chaplains “could be sacked for opposing gay marriage”.

According to the Telegraph, Sir Gerald, who left the MOD in September’s reshuffle, warned that the coalition’s equal marriage reforms could make the position of some chaplains who disagree with the change untenable.

Although ordained by churches, military chaplains are employees of the state and governed by the Equality Act.

Defence Secretary Philip Hammond, who signalled his opposition to the coalition’s policy earlier this year, is now said to be seeking legal advice on behalf of the government.

Sir Gerald is the Member for Aldershot in Hampshire, which is known as the “Home of the British Army”.

In May, Sir Gerald said the Conservative’s policy on equal marriage was a key reason for this year’s heavy local election losses for the party.

The day after the result, Sir Gerald told the BBC: “There are issues, for example, like the proposals for gay marriage.

“A lot of Conservatives have written to me saying ‘I am a lifelong Conservative, there is no mandate for this, why is this being proceeded with?’”

Sir Gerald was also staunchly opposed to the introduction of civil partnerships.

In 2005, he said: “This is a Christian country and Christian teaching is very clear on these matters and I am extremely concerned that young people today are being bombarded with literature which suggests that a homosexual relationship is the same as a heterosexual relationship, which it is not.”

He described giving gay couples in the armed forces the right to have civil partnerships as “quite upsetting for families in the married quarters.”