STOCKHOLM, March 13 (Reuters) - Sweden's Liberal Party, the smallest of the ruling coalition, said on Friday it would back bringing the anti-immigration Sweden Democrats into government after parliamentary elections in September, boosting the right's chance of victory.
The opposition left bloc currently leads in polls and the right needs to club together to have a chance of forming a government after the vote on September 13.
Until now the Liberals have said they would not support a government including the Sweden Democrats.
The Sweden Democrats have said they would not back a government they were excluded from.
The two parties have agreed on a number of political issues, including holding a referendum in 2030 on whether Sweden should join the euro zone and on a "restrictive, but humane" immigration policy.
It was not clear if a referendum on the euro was supported by the other parties on the right. Swedes rejected joining the euro in a referendum in 2003.
The Sweden Democrats are the biggest party on the right and support the current minority coalition after agreeing a broad policy platform.
The right still faces an uphill struggle to win another term. The Liberals are polling around 2% of the vote and might drop out of parliament altogether. That would probably leave the right without a majority.
The left bloc is also split and it could take some time for either bloc to form a new government after September's vote.
(Reporting by Simon Johnson, editing by Terje Solsvik)