China is set to become the most Christian country in the world, according to the Archbishop of Canterbury, Dr Rowan Williams.

Dr Williams described a "surprising" numerical expansion of Christianity in China, and also indicated there was no systematic persecution of Christians in a country once overtly hostile to any expression of religious belief.

Dr Williams said: "While there may not be systematic persecution of Christians or churches, or indeed of other religious bodies apart from certain designated sects in China, there is a situation of endemic uncertainty about what religious bodies may expect from the government."

He continued: "China is well on the way to becoming... the most heavily christianly populated country in the globe."

Speaking this afternoon at the foreign policy think-tank Chatham House, Dr Williams, who visited China for the first time last October, said it was possible for the administration in China to make life extremely difficult for Roman Catholic priests and that abuse could be arbitrary. But he insisted the abuse was not systematic.

The Archbishop also defended the Anglican stance towards the ruling Zanu PF party in Zimbabwe against accusations that the Church has not been forthright enough in its condemnation of the regime. Dr Williams said that when he met the pro-Mugabe Bishop of Harare, Right Rev Nolbert Kunonga, five weeks ago he asked him "to contemplate restoring his soul in relation to Mugabe". The Archbishop said he had asked Bishop Kunonga to back a deal that would provide food aid to the famine stricken country given by the World Food Programme and administered by the Anglican Church: "The answer was no", said Dr. Williams.

The speech, 'The Reinvention of China', was delivered at a session chaired by former Foreign Secretary, Lord Douglas Hurd. The Archbishop also discussed the future of religious institutions in China and what he called "the steady but perceivable shift" in the Chinese government's attitudes towards religious groups. But he said that the sometimes arbitrary treatment of unregistered religious bodies in the communist country could not be solved "simply by counter rhetoric, but by looking at how China could become a more pluralistic country."