After parliament voted on Nov. 14 to reject a coalition of the center-right Moderates and the Christian Democrats, with Moderates leader Ulf Kristersson as prime minister the ball is now in the social democrats' Stefan Löfven's corner. A new prime ministerial vote is likely already on Dec. 5.

It was the first time a candidate for prime minister had ever been rejected by the 349-seat Riksdagen when Kristersson was rejected earlier in November. Whether Löfvén will present the second case for a rejection by parliament remains to be seen. He will need the support from at least the Center Party but both the Center party and the Liberals have presented lists of demands to Löfvén that need to be met if they are to support the formation of a Löfvén government. Most analysts consider these demands too far-ranging for a center-left leaning government to live up to while

The speaker of parliament, Andreas Norlen, would prefer to see a prime minister vote - and a new government - before the vote on the national budget on December 12.
Next week's vote would be the second of a possible four votes before the speaker has to call for a new election.

Social Democrat leader, former and now interim Prime Minister Stefan Löfven, initially said he was willing to discuss with Annie Lööf, the leader of the Center party, should she be tapped to form a coalition. Pundits early on said either Lööf or Löfven could be next to try to form a government.

Those opposing the first coalition under Kristersson said supporting it would strengthen the anti-immigrant Sweden Democrats, the third largest party. Since 2015 when Sweden took in a record 163,000 migrants, the country has sharply restricted immigration, but many Swedes complain society cannot cope with integrating so many newcomers.

November 11, 2018:
Moderate party leader Ulf Kristersson held a press conference already Nov. 11 to withdraw his plans for a full alliance government.

The speaker Andreas Norlén nominated the Moderate party’s Ulf Kristersson as new prime minister and a prime ministerial vote will be made on Wednesday. Kristersson had to announce which parties would be included in his government no later than Monday, November 12 but the Moderate party leader confirmed on Sunday that the Liberals and the Center party were not going to be participating in the government formation.

Kristersson—if accepted by Sweden’s parliament, the Riksdag—will be leader of a two-party government with only the Moderates (M) and Christian Democrats (KD). This would be a government constellation that Sweden has never seen before. M and KD together hold only 26.1 percent of the vote and it would be the parliamentary weakest government in Sweden since Ola Ullsten's short-lived one-party government, which included only the Folkpartiet (an earlier name for the Liberals) in 1978 to 1979.

Whether Ulf Kristersson could succeed was unclear from the onset. It all depends on the Center Leader Annie Lööf and SD Leader Jimmie Åkesson. Both, who tend to perceive each other as their main political opponent, must support Ulf Kristersson in order for him to be elected. How an M and KD government would relate to SD is still unknown.
To gain the support of the Center party and the Liberals, Kristersson has assured them he intends to govern according to the common policies of the center-right coalition, the Alliance parties—even if C and L choose to stay outside. In that case, the Center party and Liberals would have been in a similar role as the earlier Left party to the center-left Löfven government. Both the Center party and the Liberals confirmed they would not be part of the intended government on Monday.
The problem for Ulf Kristersson is that the three red-green parties have a mandate more than the four alliance parties. He would need SD support in all block-breaking questions.