STOCKHOLM (Reuters) - Sweden's parliament speaker on Monday proposed Social Democrat leader Stefan Lofven as prime minister, leaving him facing a still uncertain vote to return as premier as would-be supporters continued to make conflicting demands.

       Lofven's fragile centre-left minority government collapsed last month after the Left Party withdrew its support over plans to ease some rent controls on housing.

       Those plans have since been abandoned and after the right-wing leader as expected failed to win support as premier, the speaker invited Lofven to attempt to form a new government.

       Though still uncertain, the decision could bring an at least temporary end to the renewed political turmoil stemming from the 2018 elections, which produced a nearly evenly balanced parliament and big gains for the anti-immigration Sweden Democrats, with whom several other parties refuse to deal.

       While Lofven may avoid a majority voting against him as premier - the prerequisite to be approved by the Swedish Riksdag - he still likely lacks the support needed to pass his budget bills in parliament.

       However, if he wins the upcoming parliament vote, the union boss, known as a skilled negotiator, would have months to resolve that looming impasse, though he has said he would resign once again if his budget failed to make it through parliament.

       (Reporting by Niklas Pollard and Johan Ahlander)