The Archbishop of Canterbury, Dr Rowan Williams, will be standing down from his position in December of this year, prompting speculation over his replacement and how his views on marriage for gays may change.

The 104th Archbishop, leader of the Church of England and head of a global Anglican Communion of 85 million followers will become Master of Magdalene College, Cambridge from the start of next year.

Dr Williams had expressed a comparatively liberal approach to homosexuality before his appointment as Archbishop of Canterbury but has overseen Church opposition to marriage rights for gays and a storm over gay bishops during his decade-long tenure.

His announcement comes the day after the government’s public consultation on how to introduce equal marriage rights for gays began.

He said today: “It has been an immense privilege to serve as Archbishop of Canterbury over the past decade, and moving on has not been an easy decision. During the time remaining there is much to do, and I ask your prayers and support in this period and beyond.”

He added that he hoped to have brought “vision, hope and excitement to my own ministry. I look forward, with that same support and inspiration, to continuing to serve the Church’s mission and witness as best I can in the years ahead.”

Before his appointment, Dr Williams had written in his 1989 essay The Body’s Grace: “In a church that accepts the legitimacy of contraception, the absolute condemnation of same-sex relations of intimacy must rely either on an abstract fundamentalist deployment of a number of very ambiguous biblical texts, or on a problematic and nonscriptural theory about natural complementarity, applied narrowly and crudely to physical differentiation without regard to psychological structures.”

In 2009, Dr Williams said people may have to accept “two styles of being Anglican” in order to avoid a schism after US Anglicans, including both clergy and laypeople, voted against a three-year moratorium on the consecration of gay bishops. He expressed regret that there was “no will to observe the moratorium in such a significant part of the Church in North America” to suspend the consecration of new gay bishops.

Dr Williams criticised the election of a lesbian assistant bishop in Los Angeles later in 2009, saying it was a threat to the cohesion of the Anglican Church. The Anglican Communion announced in 2010 it would suspend US Episcopalians from serving on ecumenical bodies.

By that point, Dr Williams had apologised for the language he used to discuss gay and lesbian people in the Church.

He said: “There are ways of speaking about the question that seem to ignore these human realities [of gay members of the Church] or to undervalue them; I have been criticised for doing just this, and I am profoundly sorry for the carelessness that could give such an impression.”

On Uganda’s infamous death penalty bill, Dr Williams was said to be “very clear that the private member’s bill being discussed in Uganda as drafted is entirely unacceptable from a pastoral, moral and legal point of view”.

In 2010, Dr Williams refused to support an old friend, the Rev Jeffrey John, for the post of Bishop of Southwark.

Dr John’s name was included on a secret shortlist of candidates drawn up by the Crown Nominations Commission, and the openly gay Dean of St Albans, in a celibate civil partnership, was expected to be a strong contender.

The Archbishop was reportedly blocked Dr John’s appointment. The decision came seven years after Dr John was forced to stand down from his appointment as Bishop of Reading, after it had been announced by Downing Street, and appointed Dean of St Albans.

Dr Williams’ own resignation comes one day after the opening of the government’s consultation on introducing equal marriage rights for gays, but there has been no indication the two are connected.

The Archbishop of Canterbury’s views on the subject have been expressed with characteristic elegance but have remained steadfastly opposed to full marriage equality for gay couples.

In a speech on human rights and religious faith in February, the Archbishop told an audience in Geneva that laws should restrict discrimination against gays and other minorities but should not be used to actively ‘promote change’ within a culture on issues like marriage.

He argued that while laws should prevent certain actions, including discrimination against gays, positive “change” must come from cultures themselves.

The Church of England published its position on the government’s consultation yesterday.

It said: “The Church of England is committed to the traditional understanding of the institution of marriage as being between one man and one woman.

“The Church of England supports the way civil partnerships offer same-sex couples equal rights and responsibilities to married heterosexual couples. Opening marriage to same-sex couples would confer few if any new legal rights on the part of those already in a civil partnership, yet would require multiple changes to law, with the definition of marriage having to change for everyone.

“The issue of whether marriage should be redefined to include those of the same-sex is a more complicated picture than has been painted. Arguments that suggest ‘religious marriage’ is separate and different from ‘civil marriage’, and will not be affected by the proposed redefinition, misunderstand the legal nature of marriage in this country. They mistake the form of the ceremony for the institution itself.

“Currently, the legal institution of marriage into which people enter is the same whether they marry using a civil or a religious form of ceremony. Arguments that seek to treat ‘religious marriage’ as being a different institution fail to recognise the enduring place of the established church in providing marriages that have full state recognition. The Church of England will continue to argue against changing the definition of marriage, which has supported society for so long.”

Andrew Copson, Chief Executive of the British Humanist Association, said today it would be a “dream situation” for Dr Williams to come out in favour of equal marriage once he stands down from his position in December.

George Broadhead, Secretary of the gay humanist charity the Pink Triangle Trust, said today that “nothing had changed for the better in the Anglican Church” under Dr Williams’ leadership.

He added: “The appointment of Dr Rowan Williams ten years ago was welcomed by some LGBT activists, notably Christian ones, as they believed him to be on the liberal wing of the Church of England and would take a benign stance on LGBT relationships and rights. However, they were soon disillusioned.

“It is obvious that any sympathy Williams may have had for LGBT people has been sacrificed by the need to keep his Church unified. Thus, although he condemned the murder of Ugandan gay activist David Kato, he declined to condemn the Ugandan Anglican Church from backing the hateful and draconian anti-homosexuality bill introduced in the country’s parliament.”

Speculation over Dr Williams’ replacement has so far today focused on Archbishop of York Dr John Sentamu.

Dr Sentamu has spoken more forthrightly against equal marriage rights, famously comparing Prime Minister David Cameron’s personal backing of the move to marriage equality with the actions of a dictator in January.

He told the Telegraph: “Marriage is a relationship between a man and a woman.

“I don’t think it is the role of the state to define what marriage is. It is set in tradition and history and you can’t just [change it] overnight, no matter how powerful you are.”

He then appeared to compare the prime minister to a dictator saying: “We’ve seen dictators do it in different contexts and I don’t want to redefine very clear social structures that have been in existence for a long time and then overnight the state believes it could go in a particular way.

“It’s almost like somebody telling you that the Church, whose job is to worship God [will be] an arm of the Armed Forces. They must take arms and fight. You’re completely changing tradition.”

If Dr Sentamu were to be appointed, Mr Broadhead added, it would be a case of going “from the frying pan into the fire”.

Another name tipped for the post is the current Bishop of London, Richard Chartres.

The Crown Nominations Commission will decide Dr Williams’ replacement this year.