An Italian senator has chained himself to the entrance of the Uffizi gallery in Florence in protest at the loan of a Leonardo da Vinci painting to Japan.
Senator Amato and others say the painting is too fragile to travel
Sen Paolo Amato and other leading cultural figures say The Annunciation, believed to have been painted in the 1470s, is too fragile to travel.
Many signed a petition urging Italy's culture minister to cancel the loan.
The work will be displayed in Tokyo until mid-June as the centrepiece of a trade show promoting Italian culture.
Reportedly insured for 100m euros (£68m), the artwork is due to start its journey to Japan on Tuesday.
The 15th-Century painting will be transported amid high security
Measuring 98 by 217cm (38 by 95 inches), it is to be transported in protective crates fitted with shock absorbers and sensors to measure temperature and humidity.
But protesters argue the loan is putting a masterpiece at risk for the sake of a commercial event.
Sen Amato, of former Prime Minister Silvio Berlusconi's Forza Italia party, has accused Culture Minister Francesco Rutelli of "arrogance" over his decision to agree the painting's departure.
In the eyes of Mr Amato, the minister has decided all on his own to lease out an essential part of Italy's cultural heritage, the BBC's Christian Fraser in Rome says.
Mr Rutelli has dismissed Mr Amato's outlandish protests as a publicity stunt, saying it makes everyone look very silly, our correspondent adds.
The Uffizi's director, Antonio Natali - who has consistently opposed the loan - was not there to watch the painting leave.
The work has travelled on three previous occasions - to Paris and Milan in the 1930s and for safekeeping during World War II - but this will be the first time it has left the Uffizi since 1945.
An early da Vinci work, it depicts the Angel Gabriel telling the Virgin Mary she is pregnant.