Parliamentary speaker Andreas Norlén will announce the next step in the government-building process after meeting Löfven this morning. We know that Norlén is going to ask parliament to vote on Löfven as a prime ministerial candidate, but what we don't know is when, or how likely the Social Democrat is to succeed.
The first possible date for a parliamentary vote would be Wednesday, December 12th, but it could take place after this if there's good reason to postpone it. This would happen, for example, if Löfven can convince the speaker he is holding productive talks with other party leaders and needs a bit more time to reach a compromise with them.
Wednesday is also the planned date for a parliamentary decision on next year's budget, but this could also be postponed to fit around the PM vote.
There is no set deadline by which Sweden must form a government, but the number of prime ministerial votes that can be held before a snap election is automatically called is capped at four.
The vote on Löfven will be the second chance after parliament voted down Moderates leader Ulf Kristersson. This happened after the Centre Party and Liberals refused to back a government that relied on support from the far-right Sweden Democrats. This means the country is now in untested waters — previously, parliament had always accepted the first candidate to be proposed.
In theory, a government proposal does not need a single vote in its favour in order to pass, but it will fail if a majority votes against it. A minority government can therefore be "tolerated" by abstentions, sometimes called "passive support".
In addition to support from his own party and centre-left allies the Green Party and Left Party, Löfven also needs one or more of the centre-right Centre Party, Moderates or Christian Democrats, or the far-right Sweden Democrats, to either vote for the proposal or abstain.
The most likely to do so is the Centre Party, as well as the Liberals (the fourth member of the centre-right Alliance). Both have said they are open to a Social Democrat-led government, but the latter alone does not have enough seats to prevent the proposal from failing.
If Löfven is successful, over days following the PM vote he will present a detailed statement of government and name ministers for the new government.
If he is unsuccessful, speaker Norlén will speak to each of the main party leaders before either naming a new sonderingsperson (a politician tasked with speaking to representatives of the other parties to work out what kind of government would have the support of parliament) or he may nominate another prime ministerial candidate to be voted on by parliament, which would be the third of the maximum of four such votes.