Opponents shaken and stirred at Berlusconi's 'James Bond' tunnel

President George Bush, who flies to Italy next Friday to mark the 60th anniversary of the country's liberation from the Nazis, may be the first VIP to enjoy a massive expansion of facilities at the Italian prime minister Silvio Berlusconi's holiday home on the island of Sardinia. Protected by coastguards, labourers have been working against the clock to finish a tunnel which will give visitors high security access to La Certosa, Mr Berlusconi's 47-acre estate.

Described as the "James Bond tunnel" because of its resemblance to a tunnel in the film The Spy Who Loved Me, the prime minister's tunnel is said to be equipped with a lift that will deposit visitors inside the villa. The tunnel, which local media only learnt about this week, is nearing completion and major construction activity has shifted to a 400-seat amphitheatre being constructed of pink-veined orange granite, a step away from the small castle in which Mr Berlusconi accommodates the bodyguards who escort him on his morning walks.

Italian government officials will neither confirm nor deny that Mr Bush plans to visit La Certosa. Carlo Giovanardi, Minister for Relations with Parliament, said of the tunnel: "It is just a protected mooring for the embarkation of small boats, with an underground passage. The works have been kept secret for obvious reasons of security."

When members of the Left Democrats, Italy's largest opposition party, questioned the legality of the building works, Mr Giovanardi replied: "All the necessary permits and authorisations have been given. And the prime minister pays his taxes in full." One opposition member retorted: "An amphitheatre and an artificial lake have nothing to do with security. The illegal works on his property will remain after he quits public office, which we hope will be soon."

Responding to the opposition's complaints, the public prosecutor of Tempio Pausania in Sardinia has opened an inquiry and the police in Olba, the nearest town to the villa, have carried out checks on authorisations and work in progress.

Niccolo Ghedini, Mr Berlusconi's lawyer, told the Corriere della Sera newspaper: "In the following days I will be in Sardinia to give magistrates the documents attesting to the formal and substantial regularity of everything, including the amphitheatre. I have an unimpeachable file, we are completely serene about this."

Of all the tasks that the job of prime minister throws his way, none seems to give Mr Berlusconi more pleasure than playing the gracious host. President Vladimir Putin of Russia was welcomed to La Certosa last summer and Mr Berlusconi and his resident guitarist, Mariano Apicella, who has released an album co-written by the prime minister, performed a concert of Neapolitan love songs to beguile their visitor.

It would be entirely out of character of Mr Berlusconi not to strive to offer even more splendid entertainment to George and Laura Bush, given the importance he places on his friendship with the President. The amphitheatre, however, seems too large for a concert by one guitarist and one crooner, even a crooner with an ego the size of Mr Berlusconi's. It has been rumoured that the fading Italian pop star Tony Renis, who this year directed the San Remo Song Festival, may be drafted in to bolster the bill, and perhaps the celebrated blind operatic tenor Andrea Bocelli too.

The amphitheatre's stage will be big enough to accommodate a lyric opera or a play. The theatre is said to have been the inspiration of another old friend of Mr Berlusconi's, Marcello Dell'Utri, a lover of ancient Greek tragedy. Mr Dell'Utri, a Sicilian, has been on trial in Palermo for several years on charges of Mafia association. In a separate case, he was recently convicted of extortion. He is appealing against the decision.

Mr Berlusconi bought the first seven hectares of La Certosa20 years ago from another old friend, Flavio Carboni, who this year went on trial in Rome, accused with others of murdering Roberto Calvi, the banker found hanging underneath London's Blackfriars Bridge in 1982.