China has pulled out of crucial London talks to discuss further sanctions against Iran, raising the prospect of the US, Britain and France going it alone to stop the Islamic Republic's uranium enrichment programme.

In what is seen as an indication that China will not risk its economic interests in Iran by supporting extra UN sanctions, it was confirmed that it had called off its attendance at a meeting of officials from the "P5+1" group, the five permanent members of the UN Security Council plus Germany, which was scheduled for next Monday.

Officials had been due to meet to discuss a third round of UN sanctions against President Mahmoud Ahmadinejad after it was confirmed yesterday that he had reached a landmark 3,000 operational centrifuges.

However, a Foreign Office official told Times Online today that, unless a "miracle" happened over the weekend, the meeting was now unlikely to take place.

Yesterday's report by the International Atomic Energy Agency, the UN's nuclear watchdog, confirmed that Iran had reached the landmark 3,000 operating centrifuges which is enough, according to some nuclear experts, to produce an atom bomb within a year.

China claimed that travel difficulties had caused the cancellation of Monday's meeting. However, a Foreign Office said that the country's reservations about further sanctions were also likely to have played a part.

China has extensive business interests within Iran, and - along with Russia - has opposed a third round of UN sanctions against President Ahmadinejad's regime.

The United States recently imposed its own unilateral economic sanctions and has not ruled out military action against Iran. Britain has been pushing hard for a third round of UN sanctions, including restrictions on energy and financial investment in Iran.

"Unless some kind of miracle happens over the weekend, I do not think that this meeting will take place on Monday," the source said.

Asked whether China's cancellation had taken place because of its claimed travel difficulties, or whether it was due to the country's reluctance to pursue further sanctions, the official answered: "A mixture of both."

The official added: "We want to get back around the table to discuss a new resolution. That was agreed formally last September." No fresh date for the discussions between officials - seen as crucial to hammering out differences ahead of formal Ministerial talks - has now been set.

Bronwen Maddox, Chief Foreign Commentator of The Times, said that the cancellation would make it more likely that a group of Western nations, likely to be the US, Britain, France and possibly Germany, would push ahead to develop unilateral sanctions against President Ahmadinejad's regime, and give up on the UN route.

"By this gesture, China is clearly saying that it is not going to back the push for sanctions on the basis of this report," she said.

"There is a growing feeling within the West that Britain, France, the United States and maybe Germany are going to have to do it alone."

Iran has refused to halt uranium enrichment after two previous United Nations’ sanctions resolutions and denies the West’s allegations that it wants to make atomic bombs, saying its programme is for peaceful power generation.

The West has, however, pointed to a series of hostile statements made by its hardline president, in particular threats made towards Israel, support for Hezbollah guerillas in southern Lebanon, and alleged sponsorship of terrorism against coalition forces in Iraq.

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