Rome, July 24 - Beppe Grillo, leader of the anti-establishment 5-Star Movement (M5S), should stop insulting public institutions and show more respect, House Speaker Laura Boldrini said Wednesday. ''With his aggressive and destructive language, Grillo continues to throw insults at the institutions,'' said Boldrini. ''His constant verbal attacks do not contribute, but only serve to discredit them". The M5S, which around a quarter of the vote in February's general election, said it wants to destroy the current political party system, which it claims has brought corruption and economic decline. Comedian-turned-politician Grillo frequently communicates his political thoughts via an often angry blog where no holds are barred. Last month, for example, he said the current Italian parliament was a useless "empty can of tuna" because lawmakers did little more that rubber stamp bills and decrees presented by Premier Enrico Letta's left-right government. . He also said the current parliament was illegitimate because it was elected with a much-criticised election law that he said is unconstitutional. This week, meanwhile, he accused Letta of wanting to impose a "government dictatorship". With his attacks on government, Grillo is contradicting the will of millions of Italians who voted for government representatives - including the 160-plus senators and House members of the M5S, added Boldrini in a statement.