However, if a Deputy Prime Minister has not been appointed, the Minister in the cabinet who has served the longest time (and if there are several with equal experience the one who is oldest) takes over as head of government. Note that the person acting as Prime Minister does not do so on a permanent basis: if a Prime Minister dies, resigns or loses a vote of confidence in the Riksdag, the Speaker of the Riksdag will then confer with the parties of the Riksdag and propose a new Prime Minister, who must be tolerated by a majority of the Riksdag.
In any case, if no Deputy Prime Minister has been appointed, the cabinet minister who has been in office the longest (and in the event of multiple ministers with equal length of service, the oldest) takes over as head of government. Notably, the person serving as Prime Minister does not hold this position on a permanent basis; if the Prime Minister dies, resigns, or loses confidence in the Riksdag, the Speaker of the Riksdag will confer with Riksdag parties and propose a new Prime Minister, who must be supported by a majority of the Riksdag.