Welby, who came under fire at the weekend by survivors of sexual abuse for his suggestion that the Church of England had acted with integrity, is likely to disappoint LGBTI campaigners within the church over his "cop-out" on gay sex.

Asked by Campbell if gay sex was sinful, Welby said: "You know very well that is a question I can't give a straight answer to. Sorry, badly phrased there. I should have thought that one through."

Pressed on why he could not answer, the archbishop said: "Because I don't do blanket condemnation and I haven't got a good answer to the question. I'll be really honest about that. I know I haven't got a good answer to the question. Inherently, within myself, the things that seem to me to be absolutely central are around faithfulness, stability of relationships and loving relationships."

In response to Campbell's assertion that those could be characteristics of same-sex relationships, Welby said: "I know it could be. I am also aware -- a view deeply held by tradition since long before Christianity, within the Jewish tradition -- that marriage is understood invariably as being between a man and a woman. Or, in various times, a man and several women, if you go back to the Old Testament.

"I know that the church around the world is deeply divided on this in some places, including the Anglicans and other churches, not just us, and we are -- the vast majority of the church is -- deeply against gay sex."

He added: "I am having to struggle to be faithful to the tradition, faithful to the scripture, to understand what the call and will of God is in the 21st century and to respond appropriately with an answer for all people -- not condemning them, whether I agree with them or not -- that covers both sides of the argument. And I haven't got a good answer, and I am not doing that bit of work as well as I would like."

Asked if he was trying to reconcile Anglican church leaders in places such as Uganda and more liberal churches principally in the UK and north America, Welby said: "It is irreconcilable."

Archbishop of Canterbury accused of hypocrisy by sexual abuse survivors

But, he added, homophobia was sinful "because you are hating individuals. I don't think it is sinful to say that you disagree with gay sex. But to express that by way of hatred for people is absolutely wrong in the same way as misogyny or racism is wrong."

In response to Campbell's suggestion that his answer was "morally a cop-out", Welby responded: "Yes. I am copping out because I am struggling with the issue."

The divisions within the global Anglican communion over same-sex relationships will be central to a five-day meeting of primates in Canterbury, which starts on Monday.

The meeting is expected to impose de facto sanctions on the Scottish episcopal church, which accepted same-sex marriage this summer and conducted its first same-sex wedding last week.

In January 2016, Anglican primates said the US episcopal church must face consequences for a similar move. It was barred from membership of representational bodies and excluded from decisions on policy for three years. The Canadian church is expected to follow suit on same-sex marriage.

Campaigners for LGBTI equality believe there has been a sea change in the past year within the Church of England in attitudes to same-sex relationships, and most Anglicans now support a more inclusive church.

In his GQ interview, Welby also said he hoped he would not have to preside over the Queen's funeral. "It's enormous whoever does it -- God willing someone else -- because it is an enormous public event. But as a parish priest, at every funeral you think about the enormity of it.

"I don't want to get into details because it is not something I want to talk about, but the Queen is the most extraordinary person, one of the most extraordinary people I have ever met, in every possible way. When it [her funeral] happens it will be the most extraordinary historic moment."