Mr Cameron used his trip to stress China's global responsibilities

Writing in The Sun newspaper, Mr Cameron told China to use its economic muscle to "make Mugabe see sense".

He also said the country's leaders should use their influence in Sudan to "help stop the slaughter in Darfur".

Mr Cameron has been on a four-day visit to China, which buys oil from Sudan and minerals from Zimbabwe and is a major donor of aid to both countries.

He has used his visit to argue that China's growing economic power brings with it responsibilities for global stability.

'National interest'

Speaking at Chongqing University, he said China had an interest in a "sustainable and brighter future" for Zimbabwe, which has seen inflation topping 1,000% and male life expectancy falling to 37.

More than anyone, China's political leaders could help stop the slaughter in Darfur and make Mugabe see sense David Cameron, Conservative leader

"It doesn't have to be like this," said the Tory leader.

"It shouldn't be like this. I commend the fact that China has cut back on its aid to Zimbabwe.

"I would urge you to go further and end your direct aid for the government of Zimbabwe altogether."

Mr Cameron also called on Beijing to work for stability in Sudan, which provides China with a tenth of its oil in return for substantial aid.

"Today, you are the world's third biggest importer of oil, and 10% of it comes from Sudan," he said.

"So China has a direct national interest in working for stability in Sudan, and an end to the killings in Darfur."

'Spirit of friendship'

Mr Cameron welcomed China's provision of troops for UN peacekeeping missions in Congo, East Timor and Lebanon.

But he called on the country's leaders to "bring more pressure to bear on North Korea and Burma, because the stability and prosperity of your country depends on the stability and prosperity of your neighbours".

Mr Cameron also urged Beijing to ratify and implement the International Covenant on Civil and Political Rights, telling his audience he did so in a "spirit of friendship".

"Let me make clear my hope that in the years to come, your economic opening will lead to a greater political opening too. Because it is no secret that we have differences of opinion about human rights.

"There are deep concerns about freedom of expression, of religion, about the extensive use of the death penalty, about the degree to which the media - and access for example to the internet - are curtailed.

"We make these arguments not because we think we are the moral majority, that somehow we think we have a monopoly on civilised principles, but instead, because our experience has taught us that in the long-term, progress - whether economic, social or environmental - is underpinned by the rule of law, good governance, pluralism and freedom."

'Evil' Mugabe

Mr Cameron repeated his message on Zimbabwe and Sudan in an article for Britain's biggest-selling tabloid newspaper, The Sun, saying it was time the "profound impact China is having on our world" was recognised.

He wrote: "Once Zimbabwe was Africa's breadbasket - now its people are starving and brutalised by the evil Robert Mugabe.

"In both cases, China is a massive customer - oil from Sudan, minerals from Zimbabwe - and a significant giver of aid.

"More than anyone, China's political leaders could help stop the slaughter in Darfur and make Mugabe see sense."