Left makes gains in Czech Senate election PRAGUE (Reuters) - The Czech left cemented its dominant position in the upper house of parliament in an election on Saturday, after fiscal tightening and sleaze scandals eroded support for the right. The vote adds to the woes of the centre-right cabinet of Prime Minister Petr Necas, which faces a crucial confidence vote in the lower house later this week that could trigger an early election. The government has raised taxes and curbed pension increases amid economic recession in an effort to cut the budget deficit to below the EU-prescribed 3 percent of GDP next year. There was a turnout of only 18.6 percent in the final round of the election to fill one third of the 81 seats in the upper house, the Senate. Austerity and graft accusations against high-ranking officials contributed to a debacle for the right. Necas's Civic Democrats (ODS) lost nine seats, bringing their total in the Senate down to 15, the lowest since the upper chamber was founded in 1996. "We must humbly accept this message from voters, analyze it meticulously and do everything we can so that this failure is not repeated," Necas told reporters. His party also suffered a drubbing in a regional election last weekend. The Social Democrats have also been embroiled in a high-profile corruption scandal, but the main leftist party managed to gain 13 seats in the vote, bringing the total number of its senators to 46, its highest on record. The Communist Party held one seat, keeping its tally at two in total. The Social Democrats and the Communists together have 48 seats, one less than what they need for a constitutional majority in the upper chamber. If they combine with Vladimir Dryml, the only senator for the newly formed leftist party SPOZ of former Prime Minister Milos Zeman, the left will have the power in the upper chamber to change the constitution and adopt constitutional laws. But such laws would also have to be approved by a three-fifths majority of the lower house, where the left is in a minority. The upper chamber has rejected all the main reform bills of Necas's government including those intended to reform the pension system and increase value added tax (VAT) to compensate for a drop in budget revenue. It has also rejected a bill enabling the return of church property confiscated in the communist era. To override the Senate vetoes, the government must gain the support of at least 101 deputies in the 200-seat lower house. This has become increasingly difficult as its 118-seat majority from an election in May 2010 has shrunk to 100 due to defections and the breakup of a coalition party. At the lower chamber session starting on Wednesday, the cabinet will try, for a second time, to push through a package of tax hikes needed to cut the budget deficit. Necas has combined the bill with a vote of confidence. His cabinet failed to override a Senate veto of the package on Sept 5 because six Civic Democrat rebels opposed it, saying tax hikes were against the party's program. Necas has resubmitted the legislation, threatening to quit unless it is approved. So far he has not been able to tame the rebels and the party's caucus is scheduled to meet on Tuesday to try to find a compromise. He will run for re-election in a party congress in two weeks' time. Reporting by Jana Mlcochova; editing by Andrew Roche