Andrew Foreshew-Cain, 55, the first Anglican vicar to marry his gay partner, will lead daily services at Lady Margaret Hall and be responsible for pastoral care, baptisms and funerals.

An Oxford University college has appointed a gay, married Church of England priest as its chaplain, in a direct challenge to the views of Justin Welby, the Archbishop of Canterbury.

Andrew Foreshew-Cain, 55, the first Anglican vicar to marry his gay partner, will lead daily services at Lady Margaret Hall and be responsible for pastoral care, baptisms and funerals.

His appointment coincides with the launch of Equal, a national campaign of which he is a co-founder, which is calling for the church to allow equal marriage ceremonies. At present, same-sex couples cannot marry in church, nor are they allowed to become priests once married.

This weekend, Foreshew-Cain, whose husband Stephen is a senior IT executive, compared it with the campaign to permit women to be ordained as bishops in the Church of England, which finally succeeded in 2014. He was appointed by a panel that included Alan Rusbridger, the college principal and a former editor of The Guardian, as well as senior church members.

The appointment exploits a loophole in the status of Oxford colleges. The statutes of Lady Margaret Hall state that the chaplain "shall be a clergyman of the Church of England" yet the post is not a church appointment under the Bishop of Oxford.

Foreshew-Cain does not have a licence and therefore is not permitted to lead services outside the college.

However, he told The Sunday Times that he had previously done so and intended to continue. He said any priest who illicitly invited him to lead services would be let off with a "light slap on the wrist".

He also said he would invite Steven Croft, the Bishop of Oxford, to an event to celebrate his appointment. Croft and his three suffragan bishops recently issued a public statement, Clothe Yourself With Love, which angered conservatives by urging all clergy and lay ministers to adopt a new policy of "radical inclusion" of LGBT people.

It set out five principles. They included "intrusive questioning about someone's sexual practices or desires . . . is inappropriate" and it "is . . . unacceptable to . . . insinuate . . . that sexual orientation or gender identity will be changed by faith".

Ian Paul, a conservative member of the Archbishops' Council, the church's executive body, said the appointment would generate publicity but did not have wider implications for the church; it could happen only because of the unusual status of the Oxford colleges. Next year the church is to announce how it will reconcile church doctrine with the increasing demands of the rest of society.

Many clergy, including two bishops, are in civil partnerships on the understanding that they remain celibate. However, Richard Peers, director of education for the Diocese of Liverpool, recently stated in a blog that many priests were forced to lie.

He said the lay partner of one gay priest, who had suffered mental health problems from the enforced celibacy, had been told by his doctor to "stop being so ridiculous" or get out of the relationship. Peers wrote: "I see over and over again the damaging psychological and spiritual effects of the current practice of the church."