By Andrius Sytas
VILNIUS (Reuters) - Lithuania's government lost its majority in parliament on Saturday after its junior coalition partner quit, saying they has been sidelined over policies ranging from alcohol age limits to subsidies on central heating.
A parliament vote on next year's budget, expected by early December, will be the first test for the minority government following the departure of the Social Democrats after less than a year in power.
The government will need to convince opposition parties to support it on a case-by-case basis.
The Lithuanian Farmers and Greens Union, the sole party remaining in power, have a block of 57 members in Lithuania's 141-seat parliament.
The country, once ruled from Moscow but now a member of both the European Union and NATO, is rebuilding its military in the face of an assertive Russia but has found development hampered by emigration and raising wages, eating away at competitiveness.
"All preconditions are in place for our government to continue until the next general election in 2020," Saulius Skvernelis, prime minister since November 2016, told Reuters.
"The Social Democrats took a short-sighted and suicidal decision," he added.
Lithuania's Foreign Minister Linas Linkevicius, a Social Democrat, told Reuters he will leave his party to continue in the government.
At least one of the two other Social Democrat appointees will leave the 15-member government, said Social Democrat chairman Gintautas Paluckas, elected in April this year on a reform mandate.
"Relationships within the coalition were bad, our opinions differed on almost all major issues and, since Farmers and Greens looked for votes elsewhere, we had scant possibilities to shape its politics," he told Reuters.
"This will cost us influence in the short term, but we'll be in a position to better represent our supporters in the long term," he said.
The Social Democrats, which have held power for long stretches since Lithuanian independence, have been looking for a way to reconnect with the voters after finishing a distant third in the 2016 general election.
Social Democrat rank-and-file overwhelmingly supported leaving the government in a recent poll, in contrast to the party's members of parliament who preferred staying in power.
(Reporting by Andrius Sytas; Editing by Niklas Pollard and Stephen Powell)