The collapse of a building at the 2,000-year-old Pompeii site puts a close ally of Italian prime minister Silvio Berlusconi under pressure to resign.
On Saturday, the “House of the Gladiators” collapsed in heavy rain.
Now culture minister Sandro Bondi faces a vote of no confidence in parliament.
The opposition accuses the government of letting Pompeii fall into neglect.
On Friday, staff at museums, libraries and other institutions plan to strike over budget cuts to culture.
Bondi is one of three national co-ordinators of Berlusconi’s People of Freedom party.
Although he has admitted that more buildings at Pompeii are in danger, he said that it would be wrong for him to quit over what he called long-standing problems at the site.
Since his former ally Gianfranco Fini formed is own party, Freedom and Future for Italy, Berlusconi no longer has a majority in the lower house of the Italian parliament.
Even though Fini’s bloc is unlikely to vote against Bondi, it could use the occasion to send a message to Berlusconi by abstaining.
In AD79 by a volcanic eruption from nearby Mount Vesuvius, buried Pompeii in ash, and the city was not uncovered until the 18th Century.
The house, known as the Schola Armaturarum, was used by gladiators for training before fights in the nearby amphitheatre.
Tsao Cevoli, president of Italy’s National Association of Archaeologists, called its collapse “an irreparable wound to the world’s most important archaeological site”.
Two years ago extra funds were made available and special measures were put in place in order to improve conservation at Pompeii. However critics say the plan was badly managed.
Italian heritage experts warn that many other monuments, including Bologna’s twin towers, Florence’s Cathedral and Nero’s Golden House in Rome, are also vulnerable to collapse.
“With no maintenance and non-existent funds, the whole of Italy is at risk of collapsing,” Alessandra Mottola Molfino, head of the heritage charity Our Italy, told AFP news agency.