A Conservative MP who is against same-sex marriage has criticised the Bishop of Salisbury for comparing those who oppose the reform to Christians who defended slavery and apartheid.

Last month, in a letter sent to gay Labour peer Lord Alli, the Rt Rev Nicholas Holtam distanced himself from the Church of England’s official opposition to marriage equality.

He said: “Christian morality comes from the mix of Bible, Christian tradition and our reasoned experience.

“Sometimes Christians have had to rethink the priorities of the Gospel in the light of experience.

“For example, before Wilberforce, Christians saw slavery as Biblical and part of the God-given ordering of creation. Similarly in South Africa the Dutch Reformed Church supported Apartheid because it was Biblical and part of the God-given order of creation. No one now supports either slavery or apartheid. The Biblical texts have not changed; our interpretation has.”

Bishop Holtam previously opposed marriage rights for same-sex couples, but is now the only Anglican diocesan bishop in the country to publicly favour the reform.

John Glen, MP for Salisbury and Parliamentary Private Secretary to the Communities Secretary and equal marriage supporter Eric Pickles voted against the Marriage (Same Sex Couples) Bill at second and third reading in the Commons. He has strongly criticised Bishop Holtam’s remarks.

“Many of my constituents were extremely surprised to read of the bishop’s views and I felt responsible as their elected Member of Parliament to gently challenge where he was coming from, particularly the lack of regard he had for the authority of scripture as a senior minister in our Church,” Mr Glen said to the Salisbury Journal.

“I believe the bishop knew very well how his views would be taken in terms of influencing the debate. To give the impression that people opposing same-sex marriage should be compared to those who in previous eras used the Bible to oppose slavery and uphold apartheid was a thoroughly misguided one and one that doesn’t sit well with most people’s understanding of history.”

Mr Glen accepted that with both Houses of Parliament having debated the issue “thoroughly” and large majorities being achieved in favour of equal marriage, he was not on the winning side of the argument.

He said: “While I have made my case strongly I now have to have the humility to recognise that I have lost the argument and we will have to move on.

“But for many across my constituency they remain mystified as to why this was necessary and why it was brought forward at this time, and I fear they will punish my party nationally at the next election.”

In a letter published by The Telegraph, Mr Salisbury claimed that an increasing number of congregations in Salisbury objected to same-sex marriage “not because they object to homosexuals, but because they believe marriage should follow the biblical pattern affirmed by Jesus in Matthew 19”.