(By Paul Virgo) Rome, June 21 - The government passed its first confidence-vote test in parliament on Friday when a decree on environmental emergencies was approved by the Lower House with 383 votes in favour and 154 against. It was the first time Premier Enrico Letta's left-right government used a confidence vote to speed up a measure's passage through parliament since it was installed late April after the two months of political stalemate that followed inconclusive general elections in February. If the decree, which featured funding for regions hit by earthquakes last year, had failed to win the vote, Letta's government would have fallen. Relations with Parliament Minister Dario Franceschini said the government decided to call a confidence vote "with regret" as this procedure cuts out parliament's ability to scrutinize legislation and pass amendments. But he said it was necessary, with obstructionism expected from the anti-establishment 5-Star Movement (M5S). Letta's government is seen as shaky as his centre-left Democratic Party (PD) and Berlusconi's centre-right People of Freedom (PdL) party have been almost constantly bickering about several policy issues since the traditional bitter rivals joined forces. The situation has been made even more delicate by Berlusconi's legal troubles. Senior PdL officials have said the party's lawmakers will quit if a four-year conviction for tax fraud at Berlusconi's media empire is confirmed along with a five-year ban from public office. Both Letta and Berlusconi said the government was not in danger after the three-time premier failed in a bid this week to get the Constitutional Court to strike down the fraud conviction. But Berlusconi also called the ruling the latest example of a "20-year attempt to eliminate me from political life," a charge he has made repeatedly when judges have ruled against him, often alleging a leftist plot. On Monday a Milan court is set to give its verdict in a trial into allegations Berlusconi, 76, paid for sex with an underage prostitute and abused his power to try to cover up the affair. The ex-premier is also appealing a one-year term for involvement in the publication of an illegally obtained wiretap and facing indictment for allegedly buying Senators to topple a centre-left government. Letta tried to ease the tension on Friday when he said Berlusconi's public statements had been "proper and collaborative" after the Constitutional Court's decision, though he added: "I imagine he's upset". Letta is seen as a PD moderate and is respected by the centre right, in part thanks to his uncle Gianni Letta, Berlusconi's longtime right-hand man. That relationship has been the subject of suspicion from many of Berlusconi's detractors, such as Beppe Grillo, the leader of the M5S, which opposes Letta's administration. On Friday Grillo called Letta "the most insignificant premier since the end of World War II," and said that the only thing left to see was the premier "kissing the behind of Berlusconi to survive as long as possible". While he directs his fire at Letta, comedian-turned-politician Grillo is also still facing dissent within his own movement, which captured around a quarter of the vote in the general election. Senator Paola De Pin said Friday she was leaving the M5S in solidarity with another Senate member, Adele Gambaro, who was ejected this week. "After much painful reflection, I announce my exit from the 5-Star Movement," said De Pin, voicing her "full solidarity with Adele Gambaro" and disapproval of her "pillory before the media". On Wednesday the party rank and file voted online to eject Gambaro for criticizing Grillo, calling him "a problem for the movement" after the bloc's poor showing at local elections across Italy. Her defection is the first since Gambaro was expelled, to the opposition of a significant number of M5S Senators and MPs. Many believe that a party schism is imminent.