Only days after saying he would not knowingly ordain gay priests, the new spiritual head of the Church of England said on Sunday that "faithful" homosexual relationships do not conflict with the teachings of the Bible.
"If the Bible is very clear - as I think it is - that a heterosexual indulging in homosexual activity for the sake of variety and gratification is not following the will of God - does that automatically say that that is the only sort of homosexual activity there could ever be?
"My own personal conclusion is that I can see a case for acknowledging faithful same sex relationships," he said in the An Archbishop Like This TV programme which aired the day before he officially takes office.
Archbishop Williams, who is regarded as a formidable intellectual, has been under fire from church traditionalists for being making known his liberal views on women priests and gay rights.
In the programme, Archbishop Williams also repeated his views on severing the church's links with the state, while condemning the Anglican hierarchy's "profoundly unchristian" concern with status.
Last week, he announced that he planned to abide by the policy of the Church and guaranteed he would no longer knowingly ordain a gay priest.
The 52-year-old was appointed in July to succeed George Carey as the spiritual leader of around 70 million Anglicans worldwide. Archbishop Williams will be confirmed at St Paul's Cathedral on Monday, prior to his enthronement at Canterbury in February.
Queen Elizabeth II is the supreme head of the Church of England.