The next five days will show whether President Ahmadinejad gets what appears to be his wish: a growing row with the West over Iran’s nuclear ambitions. Despite deep unease within the regime about his taste for confrontation, the chances are that he will.

There is good news for those who want Iran to back down: factions within the top leadership are now fighting with each other about whether to risk defiance of the United Nations Security Council. The bad news is that none of them, even the so-called moderates, appears to want to give up uranium enrichment, the work that could give Iran nuclear weapons.

The worse news is that the countries trying to curb Tehran are even more divided among themselves than are Iranian leaders. On Monday a meeting in Brussels of the five permanent members of the Security Council may well show that the US, Britain and France do not have support from China and Russia for more sanctions, and will have to try their best alone.

That meeting will follow reports from the International Atomic Energy Agency, the UN watchdog, and Javier Solana, the European Union foreign policy chief. They are about to say whether they think Iran has disclosed as much as it is obliged about its nuclear work. Both are expected to say that it has not, Solana the more bluntly.

It is no surprise that the divisions within the Iranian regime, always there, and getting noisier, have burst into the open under the pressure of these deadlines. On Monday, Ahmadinejad railed at critics who wanted Iran to take a less inflammatory approach. He didn’t name his targets, beyond calling them “domestic elements”, but it would be fair to take this as a gibe at Hashemi Rafsanjani, the former President, and his allies.

Rafsanjani, a figure so deeply woven into business and political life that Ahmadinejad has been unable to brush him away, is often described as a moderate, but that is only in comparison with Ahmadinejad. But whether out of desire to protect his commercial interests from sanctions or the loftier pursuit of national interest, as he claims, he has urged him to take the heat out of this row.

He has had some support. A month ago Ahmadinejad pushed out Ali Larijani, the chief nuclear negotiator and another moderate (in tone at least), but Larijani was reinstated within days. That is a sign that the President does face constraints. He may be the single, belligerent face of Iran abroad, but clerics and pragmatic politicians have been alarmed by his eruptions.

Nor is his popular base as strong as it was. He was elected in June 2005 for promising to put the rewards of the oil boom on the tables of the poor, but many feel he has failed. Iran’s inability to refine enough of its own oil means that it imports 40 per cent of its petrol, and rising oil prices are a mixed blessing. Its lack of refineries reflects the bite of past sanctions and offers hope that its nuclear work will not go smoothly either.

But none of Ahmadinejad’s critics is pushing the regime to drop enrichment entirely, still the West’s target. They have little reason to make that concession; in the past week China has reaffirmed its support.

Chinese officials said yesterday that their drive to invest in Iran’s biggest undeveloped oilfield in return for gas had been slowed down by tough negotiations, not the prospect of more sanctions. If China continues to resist the push for sanctions, led by the US, Britain and France, then those three countries, perhaps joined by Germany, may have to go it alone.

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