STOCKHOLM (AFP) - Sweden holds legislative elections on Sunday (Sept 9), with polls predicting a parliamentary deadlock as neither Prime Minister Stefan Lofven's left-wing bloc nor the opposition centre-right are seen winning a majority, while the far-right makes gains.
"It's difficult to single out the most likely (government) scenario" after the election, University of Gothenburg political scientist Ulf Bjereld said.
"Instead you have to look for the least unlikely scenarios," he said.
One thing is certain: Sweden is headed for a period of uncertainty, with a weak minority government triggering fears of new elections, at a time when economists are forecasting a likely downturn during the next four-year mandate.
Traditionally in Sweden after the election, the outgoing speaker of parliament consults with party leaders to nominate a candidate for prime minister tasked with forming a government.
Parliament votes on the speaker's choice, and can reject his proposal four times, after which new elections must be called. Sweden has not held a snap election since 1958.
The post-election scenario seen as most likely by political observers is a new Lofven government, albeit with an even weaker minority than it has now.
The outgoing "red-green" bloc - made up of the governing Social Democrats and the Greens, with the informal support in parliament of the ex-communist Left Party - is leading in the polls ahead of the centre-right Alliance.
If Mr Lofven were to stay in power with a weakened minority, he would likely try to rally the support of two Alliance members, the Centre Party and the Liberals, to pass legislation, finding common ground on issues like immigration, integration and gender equality.
The far-right Sweden Democrats however have vowed to topple a minority left-wing government, for example during the vote on the autumn budget bill.
The conservative Moderates Party leader Ulf Kristersson is intent on ousting Mr Lofven.
Despite some ideological differences, notably on immigration, the four centre-right Alliance parties which governed between 2006 and 2014 (the Moderates, Centre, Liberals and Christian Democrats) have agreed to build a coalition government.
Easier said than done: the Alliance would need the support of the far-right to pass legislation, and the far-right would make demands in exchange for its backing.
It would either ask for policy concessions - which the four parties have so far ruled out - or key positions on parliamentary commissions that draft legislation.
One uncertainty in this scenario is the score of the Christian Democrats.
Opinion polls have long credited the party with less than the four per cent required to be represented in parliament, though towards the end of the campaign they appeared to be comfortably above the bar.
If the two previous scenarios were to fail, the Social Democrats could choose to invite the Liberal and Centre parties to the negotiating table.
While Mr Lofven has insisted that he wants to continue to govern with the Greens, he has not ruled out such a possibility. They would have to overcome major differences though, in particular on the budget.
Such a collaboration would signal the end of the centre-right Alliance.
With a wave of populism sweeping across many countries in recent years, some political analysts have suggested that opinion polls may be underestimating support for the far-right Sweden Democrats (SD).
They have not ruled out the possibility the SD could end up being the biggest party.
However, SD would find itself isolated, unable to build a government or majority in parliament.
The head of the party, Mr Jimmie Akesson, doesn't believe in such a scenario himself, seeing instead a collaboration with the Moderates in such a case.