“You can’t hold an elected position within the Social Democrats unless you can fully stand up for the party’s values that all human beings are equal and for equality between women and men,” Löfven said.
“These are the values which we base our whole political platform on. This is inviolable.”
Löfven comments were made during a visit to Härnosand in northern Sweden on Saturday in response to a question from news agency TT whether Mustafa could remain as chair of the Islamic Association (Islamiska förbundet).
The association’s bylaws state that women and men hold different legal status.
Omar Mustafa was chosen to sit on the governing board of the left-of-centre opposition party at last weekend’s party congress.
The election has proved controversial with much of the criticism directed at Mustafa concerning an invitation issued by the Islamic Association to speakers with known anti-Semitic views.
In an open letter to the Swedish Aftonbladet daily on Friday, Omar Mustafa expressed understanding of the criticism and distanced himself from the decision to invite Egyptians Salah Sultan and Ragheb Al-Serjany.
Salah Sultan is on record as having said in an interview with al-Jazeera that Jews kill Christians at Easter, and Ragheb Al-Serjany has publicly said Jews control the international media.
Löfven, who has not spoken to Omar Mustafa himself, on Friday expressed satisfaction at his colleague’s explanation.
“(Mustafa) has himself said that he didn’t think it was OK to give these people access, and because he has also said he stands up against anti-Semtimism, I think the situation is OK,” Löfven told Aftonbladet.
Löfven pointed out on Saturday that the responsibility to deal with the situation concerning Omar Mustafa’s position rests with the Stockholm branch of the party, as they nominated him.