Who’s going to be the next president of Iran? It looks ever more likely that it will be the current one, Mahmoud Ahmadinejad. In that case, British and US tactics, which have been based on the hope that Iranians would kick him out, will have to adapt to four more years of a leader who has yielded not an inch to their pressure over his country’s nuclear programme.

Several months ago chances of a strong moderate contender winning the presidency in the June 12 elections looked better than they do now. Yesterday the Guardian Council approved three candidates to run against Ahmadinejad, but even though the line-up includes two moderates, analysts reckon they face an uphill struggle.

Yesterday, too, Iran test-fired a medium-range missile capable of reaching Israel and US bases in the Middle East. That is a provocative gesture only two days after President Obama urged leaders in Tehran to accept his offer of dialogue, and warned that it would not be open for ever. Clearly, the missile launch does not represent a warm welcome for the US overtures. But it is probably better seen as a pre-election broadcast by Ahmadinejad — a message that he will not soften his tough line on the US and Israel. The council’s decision on the four permitted candidates — out of 475 applicants — sets up a race between Ahmadinejad, in the hardline camp, and two moderates and a hardliner to challenge him. The moderates are Mir Hossein Mousavi, a former Prime Minister, seen by many as the greatest threat to Ahmadinejad, and Mahdi Karroubi, former Speaker of parliament. The council has rejected moderates in the past but these two are thought too prominent to suffer that treatment. The fourth runner is Mohsen Rezaei, a former leader of the Revolutionary Guards and well-known conservative.

All three challengers agree on one point: Ahmadinejad has mismanaged the economy.

They are right that this is his weakest flank. He swept to power four years ago, in a shock result, because of his promise to put oil riches on the tables of the poor. He has kept his promise to spend a lot, but the effects have been patchy. The plunge in the oil price has now squeezed finances, making it hard to pay subsidies on fuel and food. It is a measure of Iran’s isolation that it lacks refineries to turn its own oil into petrol, and has to import it.

Yet Ahmadinejad has won points at home for improving ties with Latin America and Africa, for staying cool when given a hostile reception at Columbia University in New York in 2007, and for generally restoring national pride. In contrast to his reputation in the US as a dangerous extremist, he is seen by many at home as a careful, tough negotiator. He also appears to have the backing of Ayatollah Sayyid Ali Khamenei, Iran’s Supreme Leader, which could prove the most valuable factor.

The reformers argue for better ties with the West. They say that in persisting with the nuclear work (which Iran says is to support reactors, but the US and Britain suspect is designed to bring weapons capability within easy reach), the country has paid too high a price in sanctions. Many Iranians share these pro-US instincts.

Yet it would be wrong to expect any president to give up easily a programme that also has widespread support.

On Monday Binyamin Netanyahu, Israel’s Prime Minister, tried to persuade Obama to put the acute threat that he believes Iran poses to Israel above the stalled talks with the Palestinians. Obama met him half way. He repeated his offer to Iran of the first direct talks since the Iranian revolution — but warned that US patience might not last past the end of the year.

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