By Simon Johnson and Johan Sennero
STOCKHOLM (Reuters) - The leader of Sweden's Social Democrats, Stefan Lofven, on Monday abandoned efforts to form a government, extending a political deadlock that has gripped the country since an inconclusive national election seven weeks ago.
The failed attempt brought the prospect of a snap election closer, though the speaker of parliament said he would try to avoid that at all costs.
The Sept. 9 vote gave the anti-immigrant Sweden Democrats hold the balance of power, but neither Lofven's center-left bloc nor the center-right group of parties has been willing to give them a say in policy due to their white supremacist roots.
"In light of the responses I have had so far ... the possibility does not exist for me to build a government that can be accepted by parliament," Lofven told reporters.
The center-right Alliance bloc's leader, Ulf Kristersson, has already tried and failed to form a government.
Speaker Andreas Norlen, who on Monday held talks with all the party leaders, said he would not, at least for now, ask anyone else to try to form a government.
Instead, he would on Tuesday take on a more active role in trying to mediate a way to forming a viable coalition. He would propose a prime minister to parliament at least once during the autumn, in order if possible to avoid another election.
"A snap election would be a big defeat for the Swedish political system," he told reporters.
A caretaker administration under Lofven has run Sweden since last month's ballot.
The delay in forming a permanent government could further undermine faith in mainstream parties. Sweden Democrats leader Jimmie Akesson said a new vote could boost support for his party.
Both Lofven and Kristersson said they still hope to be prime minister, but neither offered a way to end the stalemate.
"I do not see any indication that anyone has changed their minds about anything at all," Kristersson told reporters after meeting speaker Norlen.
Graphic - Swedish election scenarios: https://tmsnrt.rs/2p45tJh
(Reporting by Johan Sennero; editing by John Stonestreet)