The decision comes less than three weeks after Stenevi took an indefinite period of sick leave, saying that she needed time to recover after a bruising period that saw the party launch an internal investigation into complaints about her management style.

There has also been extensive press coverage over the alleged conflict she has with Daniel Hellden, the man chosen as the party’s other leader at a conference in November. 

“This is a very difficult decision,” Stenevi told the Aftonbladet newspaper. “I put myself forward for reelection and received a renewed mandate from the congress, but I don’t believe I can be my best self right now and I don’t really know how long it will take to get back on my feet.”

“The party deserves better than to be in some kind of limbo, where one of the spokespeople [as the party calls its leaders] cannot fully carry out the role. And I need to focus on getting better again, being a good mum and a pleasant partner.”  

Writing on Instagram, Stenevi’s joint leader Daniel Helldén said that he was sorry to see Stenevi go. 

“I have respect for her decision, but personally I think it’s a real shame. I have very much enjoyed working together with Märtha,” he said. 

Stenevi said that the leaks to the media about complaints about her management style in the autumn had been difficult for her to handle. 

“It put me under enormous pressure. It wasn’t the media attention: I understand that you are going to be continually criticised and investigated, but what happened in the autumn was that there was a lot of anonymous briefing, so you didn’t know who you could trust or where it was coming from, and that made it much more difficult and much more draining.” 

When Stenevi went on sick leave last month, the party’s secretary, Katrin Wissing, told TT that her relationship with Daniel Helldén had not played a role in her departure.

“On the contrary, Daniel has been giving Märta extremely good support,” she said. 

Although Stenevi is resigning as party leader, she intends to remain in parliament is an MP, and has not decided to give up her career in politics. 

“When I’m back on track, I’ll see what happens, but I don’t feel completely finished with politics,” she said. “But this is the right decision, both for me, my family and my party.”