A national anti-government protest by the opposition Italy of Values (IDV) party set for July 8 was thrown into doubt on Wednesday after a scathing attack on Napolitano by one of its organisers.
The president came under fire after he sent a letter rapping the Italian judiciary's self-governing body for announcing that the government's trial-freeze measure was unconstitutional.
Napolitano told the Supreme Council of Magistrates (CSM) it could not express opinions on whether bills up for debate were constitutional, since this was the job of the Constitutional Court, and urged it not to interfere with parliament's role.
The president called for ''reciprocal respect'' and for an end to ''confusion'' between the roles played by the judiciary, the executive and legislative branches of the state.
But IDV protest organiser, philosopher Paolo Fores D'Arcais, said Napolitano's letter was ''shameful''.
''It's the CSM's job to give an opinion on the law. It's it's duty,'' D'Arcais said.
Politicians from both the government and other opposition parties rallied to the president's defence.
''Is D'Arcais asking Italians to protest in the squares (on July 8) against the president of the republic?'' asked Federica Mogherini of the opposition Democratic Party (PD).
Another of the protest's organisers, the PD's Furio Colombo, said he would refuse to participate on July 8 unless ''it was made clear that the manifestation is against the government alone''.
IDV leader and ex-graftbuster Antonio Di Pietro was quick to distance himself from D'Arcais' attack, describing it as ''entirely inappropriate'' and adding that Napolitano's message to the CSM was ''exemplary''.
''It underlines and reinforces the autonomous faculty of the CSM to send opinions to parliament and to the government on measures that regard the administration of justice while defining, at the same time, the unique limit of that faculty, which is the CSM's lack of jurisdiction to express an opinion on whether a measure is unconstitutional,'' he said.
On Tuesday Justice Minister Angelino Alfano said he welcomed Napolitano's intervention, which he described as ''wise'', while Berlusconi said he ''didn't have anything to add'' to the president's comments.
