Never mind the football hooligans. The thorniest political dilemma facing Germany as it prepares to host the World Cup is what to do about Mahmoud Ahmadinejad, Iran’s hardline president, if he insists on coming to watch his team play next month.

Germany is obliged to admit the head of state of a participating nation, and the tournament’s official motto is "A Time To Make Friends". But Mr Ahmadinejad has demanded Israel’s destruction and has repeatedly denied the holocaust - a crime in Germany.

By unhappy coincidence Iran’s first match is in the stadium on the Nuremberg complex used by Hitler for his mass rallies, and German neo-Nazis are planning a march in support of Mr Ahmadinejad. But Israel, Iranian exiles and leading German politicans are demanding that he is kept away.

"The question is whether Germany as host can prevent the visit of a head of state who has shown himself to be a repulsive and embarrassing anti-Semite," said Ehud Olmert, the Israeli Prime Minister. "The spirit of the World Cup is in absolute contradiction to the spirit that he represents."

An angry editorial comment in the Jerusalem Post this week accused Germany of trading with Iran, and appeasing its nuclear ambitions, and continued: "Germany’s behaviour toward Iran is a clear sign that for all its Holocaust memorialising, for all its anti-Nazi legislation, and for all its protestations of friendship with Israel and the Jewish people, Germany has not learned the lessons of the Holocaust."

The paper declared: "Ahmadinejad should be arrested when he sets foot on German soil."

Some German politicians agree. Edmund Stoiber, Prime Minister of Bavaria, says: "Such a man is not welcome."

But the German government is pressing ahead anyway. Wolfgang Schaeuble, Interior Minister, says that the president "can naturally come to the matches". Differences of opinion over the Holocaust, Israel and nuclear power could be aired during the visit.

Herr Schauble’s deputy, August Hanning - a former head of the German Security Service - has already agreed with Tehran that there should be no political demonstrations in the stadiums.

Moreover the Iranians and Germans will exchange intelligence ahead of the World Cup. "When the Iranians fear a threat, they will tell us their reasons," said Herr Hanning. "Then our evaluation will flow back to Tehran."

For Iranian exiles - expected to attend the matches against Mexico, Angola and Portugal in large numbers - that smacks of appeasement.

"Naturally we’re worried that information from the Germans will be used against our families in Iran," said Hassan Nayeb-Agha who played as a midfielder for Iran in the 1978 World Cup. "We must not let the Iranian regime misuse the World Cup in the same way that Hitler did with the Olympic Games in 1936."

Iran is expected to take a final decision on whether Mr Ahmadinejad should travel to Germany within the next few days, but there is little doubt that he wants to go. "Our president loves soccer," said the head of the Iranian Football Association, Muhammad Ali Dadkan as he inspected the Nuremberg pitch last month.

One Israeli lawyer living in Germany has lodged an application with the federal prosecutor to issue an international arrest warrant on the president as soon as he gets off the plane.

But the president would probably enjoy diplomatic immunity, and some lawyers doubt his denial of the Holocaust breaches German law as his comments were made abroad. A bigger problem would emerge if he repeated those comments while in Germany.

In the meantime Mr Ahmadinejad appears to be trying to please Germans ahead of his visit: "Germans should not feel guilty because a certain number of Jews were killed during World War Two," he said last week.

"The president himself does not seem to realise how repulsive his comments are to Germans," said one senior official. "He seems to think that he is flattering us."

For Germany the best solution would be for Brussels to impose a Europe-wide entry ban on members of the Iranian leadership. A similar boycott is in place against the Belarusian leadership. "This would be an elegant solution," said one German official.

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