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By Pawel Sobczak and Christian Lowe
WARSAW, Sept 9 (Reuters) - Polish Prime Minister Donald Tusk's majority in parliament was reduced to two seats on Monday by the departure of the leader of a conservative faction following months of internal wrangling and falling opinion poll ratings.
Jaroslaw Gowin, who unsuccessfully challenged Tusk for the party's leadership in a formal vote last month, is the second MP to depart in the past two weeks amid disciplinary action against members of the conservative grouping.
Tusk should still be able to get most laws through the 460-seat lower house of parliament, but his once-robust grip on power is now looking more fragile than at any point in his six years in office.
A first test for his reduced majority will come when parliament votes on a government law that will involve transferring some assets from private pension funds to the state. Opponents, including some in Tusk's own party, say it amounts to a nationalisation.
Gowin, a former justice minister in Tusk's government, announced he was leaving the party because he could no longer support its policies, on the pension reform and other issues.
"Politicians putting their hands on 270 billion zlotys has to lead to a reduction in pensions for millions of Poles," he told reporters.
"I do not agree with such a policy, this is not the Civic Platform's program. This is why I took the decision to quit the Civic Platform," he said. "Remaining in the party would be contrary to my conscience."
Gowin's departure caps months of internal wrangling. Gowin was the leader of an informal conservative faction within Tusk's Civic Platform party which believed the prime minister was too liberal on issues such as same-sex partnerships and abortion.
At the end of last month, Nigerian-born Civic Platform lawmaker John Godson, who is on the same wing of the party as Gowin, said he was quitting.
A third member of the conservative faction, Jacek Zalek, is facing disciplinary action by the party and could also quit, say party insiders.
That would leave Tusk with a wafer-thin majority of one vote in parliament. Political analysts say that Civic Platform party managers can usually bolster their support by persuading a handful of independents to back the government.
However, a defeat on an important vote could bring down the government, forcing either a re-configuration of the governing coalition or, if that fails, an early election. The next scheduled election is in 2015. (Reporting By Karolina Slowikowska; editing by Patrick Graham)