About 39% of Italians agree with attacks by M5S on president
Disapproval of efforts by Grillo to impeach Napolitano at 38%31 January, 15:14
But that same group said they did not agree with the tone of the attacks, according to the survey by pollsters Ixe for RAI 3 television's program Agora.
An almost equal number - 38% - said the attacks by the M5S, which is trying to impeach Napolitano, and the party's tone were out of line.
The survey was conducted on 1,000 people and has a margin of error of plus or minus 3.1%.
Among confirmed M5S supporters, only 10% said the attacks were unjustifiable, while 38% said the tone was wrong but the attacks were legitimate.
The anti-establishment M5S submitted a petition to parliament on Thursday seeking to impeach Giorgio Napolitano for "attacking the Constitution".
The M5S said Napolitano had breached the Constitution by failing to send back unconstitutional laws to parliament and abusing his power of pardon, among other things.
The 88-year-old statesman is serving an unprecedented second term as president after being re-elected last spring to help overcome the political deadlock resulting from inconclusive parliamentary elections in February.