To form a new government you need to be nominated by the outgoing speaker (who right now is conducting talks with the party leaders) and not be opposed by a majority in parliament. A PM then presents his or her ministers and the PM can rule until opposed by a majority (even if elections are held the PM can continue until opposed). If four people are nominated and refused, new elections are automatic. This has never happened, indeed we have never had more then one vote on government formation.

But to rule you need to be able to pass a budget. The budget is passed that gets the most votes. Normally, each party votes for their own budget and when the budget of main opposition party faces of against the governments budget, the smaller parties abstain. However, the former government are claiming that they will present and vote for a common budget at least this fall. That is 142 votes. A red-green government has 137 votes. If they get support from the left party they can pass a budget, unless the racist twits feels like toppling a left wing government. So right now, the negotiations are between a prospective red-green government and the Centre Party (farmers) and Liberal People's Party to have their support for at least the first budget. The left party is left in the cold (which might be a good thing, long term, as they will not share the blame directed at the government).

Sweden's finest (and perhaps only) collaborative, leftist e-newspaper Synapze.se