The leader of the Moderates party, craftsman of an unprecedented rapprochement between the traditional right and the nationalist camp in the legislative elections of September, gathered 176 votes for his election as head of government, for 173 against.
After eight years on the left in power, he succeeds the head of the Social Democratic government Magdalena Andersson, who ensured the transition after presenting her resignation after very close elections.
The vote was greeted by applause from the benches of the three right-wing parties (Moderates, Christian Democrats, Liberals) which will form the future government, and the SD, the very influential first formation of the majority with 73 seats.
To become Prime Minister, Ulf Kristersson, 58, did not have to have an absolute majority against him.
"Now change is possible," he said at a press conference after his election, expressing his "humility in the face of the tasks ahead of us."
On Friday, after several weeks of negotiations, the leader of the Swedish right presented a political agreement with the three other leaders of majority partner parties, including SD boss Jimmie Åkesson.
At 43, the latter had been the big winner of the September 11 elections, with a record score of 20.5% of the vote and the new rank of Sweden's second party behind the outgoing Social Democrats.
In their 62-page roadmap presented Friday, the four parties include measures to fight crime and reduce immigration, as well as a revival of nuclear energy that Sweden had reabsorbed in recent decades.
The new government, expected on Tuesday, plans, among other things, drastic cuts in Sweden's refugee reception policy, reducing the quota from 6,400 last year to 900 per year during the four years in office, as well as the possibility "of deport foreigners for misconduct".
- Fragile majority -
With serious problems with criminal gangs and bloody settling of scores, Ulf Kristersson had made security a key part of his election platform alongside promises to rein in Ukraine's war-torn energy prices.
"Crime is a very big commitment of this government," he said Monday, when asked about his new executive's priority.
Never in Swedish political history has the far right been part of a majority, against a backdrop of nationalist pressure in several European countries.
The program also plans to authorize searches without suspicious behavior in certain sensitive neighborhoods, heavier penalties for repeat offenders and the possibility of testifying anonymously in court.
As Monday's vote reflects, the "constellation" of the rights has a narrow absolute majority of 176 seats against 173 for the opposition led by Magdalena Andersson.
After an election so tight that the final results had to wait three days, Ulf Kristersson was tasked a month ago with forming a government.
The great challenge of the new executive was to reconcile the contradictory expectations of the small Liberal party, whose red line was the accession of the far right to government, and the influence of the SD, who claimed ministerial posts.
Even outside the government, the latter on Monday hailed their "absolutely decisive role" in the majority.
Both as "the largest party among the four in the government document, and as the parliamentary guarantor of the government which will take office", welcomed Mr. Åkesson.
The SD also won their case on the unemployment benefit file. The party, which describes itself as "socially conservative", was opposed to compensation cuts proposed by Mr Kristersson.
Due to the weaknesses of the new majority, the left, back in opposition, has not given up hope of returning to power before the next elections scheduled for 2026.
The heavy influence of the SD in the program announced on Friday has sparked tensions within the Liberals, whose support is essential to Ulf Kristersson.