The disestablishment of the Church of England would 'not be a disaster', according to the archbishop of Canterbury.

Speaking to the Guardian today, Justin Welby said separating the Church from the state would be a complicated process, but added 'Nothing's a disaster with God.'

The role of the Church in national life is to be highlighted tomorrow at the wedding of Prince Harry and Meghan Markle in St George's Chapel, Windsor. The decline in church attendance and Christian allegiance in England has led to increasing questions over the established status of the Church, some of whose bishops sit in the House of Lords.

Welby told the Guardian: 'I think, in the end, establishment as a legal thing is a conglomeration of different bits of history, there's no "Establishment of the Church of England Act" that you could repeal – it's a complicated process.

'And if you mean by privilege that the archbishop of Canterbury very often is involved in royal weddings, or crowns the monarch or whatever, that's really a decision for parliament and people.'

He said he would like to stay in his current role until he retired at 70 and that he was most proud so far of the ordination of women as bishops, adding he would like to see a woman in the Canterbury role at some point.

Of the issue of sexual abuse, he said that 'to fail in safeguarding children and vulnerable adults is the absolute denial of what we are called to in Jesus Christ. Jesus calls us above all to care for the vulnerable and the poor and the weak. And to privilege the institution over that is utterly shameful and wrong and must never be allowed to happen.' He warned against the danger of worrying 'more about our reputation than the truth'.