The leader of Italy 's populist Northern League party, Umberto Bossi, resigned as reforms minister, knocking a pillar from beneath Prime Minister Silvio Berlusconi's increasingly fragile government.
His decision to resign was sparked by weeks of ferocious in-fighting within Berlusconi's coalition and raises questions about the League's long-term commitment to the government.
The head of the lower house of parliament announced that Bossi, who is convalescing in a Swiss hospital after suffering heart failure in March, would also leave Italy 's national parliament and take up a seat in the European parliament.
The Northern League said in a statement it did not intend to bring down the government. Other League politicians will remain in the 3-year-old government, but without Bossi to instil order amongst his parliamentarians, it will prove difficult for Berlusconi to push through much-needed economic reforms.
The Northern League was infuriated by the recent ousting of Economy Minister Giulio Tremonti, who fell foul of cabinet feuds, and worried that the in-fighting would sink its cherished plans to hand more executive powers to the Italian regions.
Bossi's decision to quit sent a signal to his government colleagues that he will not let his small, vocal party be taken for granted during his prolonged illness.
The League brought down Berlusconi's 1994 government after only seven months in a row sparked by pension reform. This time around, Bossi has proved the prime minister's most reliable and tenacious ally.