An Anglican minister has sparked outrage after questioning whether Prince George is gay and if that might force the Church of England to adopt same-sex marriage.

The Very Rev Kelvin Holdsworth, Provost of St Mary's Cathedral, Glasgow, and a campaigner for LGBT rights in the Church, was accused of a 'cynical' and 'sinister' attempt to manipulate the royal engagement for his own ends after he suggested 'the fastest way to make the C of E more inclusive [is] to pray for Prince George to be blessed one day with the love of a fine young gentleman'.

The comments about the four-year-old, who is third in line to the throne, were made in a blog he re-posted after the announcement of Prince Harry and Meghan Markle's engagement.

Gavin Ashenden, a former Chaplain to the Queen and missionary bishop in the Christian Episcopal Church, accused Holdsworth of praying the 'child out of the intentions of God'. He told Christian Today: 'To pray for Prince George to grow up in that way, particularly when part of the expectation is he will inherit is to produce a biological heir with a woman he loves, is to pray in a way that would disable and undermine his constitutional and personal role.

'It is an unkind and destabilising prayer. It is the theological equivalent of the curse of the wicked fairy in one of the fairy tales. It is un-Christian as well as being anti-constitutional. It is a very long way from being a blessing for Prince George.'

Lee Gatiss, director of the Church Society, a conservative Christian body, said it was a 'cynical, secular, and sinister in its approach to spiritual matters'. 

He told Christian Today: 'To co-opt the Royal children to service a narrow sexual agenda seems particular tasteless and, I should add, bizarrely illogical on his own grounds. Is he saying no one can "pray the gay away" but you can pray it into someone?'

Susie Leafe, director of the conservative Anglican grouping Reform, said it was clear Holdsworth would 'use any means to achieve his aim' of seeing same-sex marriage in church.

'It is disappointing that he feels it necessary to bring a four year old Prince into the argument,' she told Christian Today. 'As a clergyman I would have thought his prayers for Prince George should be focused on him growing up to know the saving love of the Lord Jesus rather than the "love of a fine young gentleman".'

Holdsworth's article lists strategy ideas for campaigners to change the Church of England's opposition to gay marriage. In it he suggests: 'If people don't want to engage in campaigning in this way, they do in England have another unique option, which is to pray in the privacy of their hearts (or in public if they dare) for the Lord to bless Prince George with a love, when he grows up, of a fine young gentleman.

'A royal wedding might sort things out remarkably easily though we might have to wait 25 years for that to happen. Who knows whether that might be sooner than things might work out by other means?'

The Scottish Episcopal Church voted to allow priests to marry same-sex couples if they want to, with a conscience clause for those who object. However the Church of England does not allow gay couples to marry in church, holding to its teaching that marriage is just between one man and one woman.

Holdsworth is a long time campaigner in favour of gay marriage across the worldwide Anglican Communion.

This is not the first time he has courted controversy. In January he invited a Muslim to recite from the Koran during a service at the Cathedral, with the passage including a denial that Jesus was the son of God – a key Christian doctrine.

The Archbishop of Canterbury was urged to intervene and the controversy prompted Ashenden to resign as one of the chaplains to the Queen, citing his inability to speak freely about the issue.

Christian Today has contacted St Mary's Cathedral for comment.