"The party told me the pressure from the media was too big and that they wanted to focus on talking about jobs," said Mustafa as he broke his media silence on Tuesday at a secret location with police present.
"The party neither wanted nor knew how to ward off the media storm."
"I am neither a terrorist nor a fundamentalist and I don't advocate violence," said a visibly tired Mustafa in response to a question about whether he was an Islamist.
He revealed on Tuesday that in talks with the party behind closed doors, it was not enough when he offered to quit the chair of the Islamic Association. The party, he said, in the end buckled under pressure from the "Islamophobic media storm". The party's leadership communicated that he could not stay on as substitute member of the governing board.
Six days after his election to the governing board as a representative for the party's Stockholm district (Arbetarekommun) he left the post, as well as all his commitments in the party.
"I feel the full truth hasn't come out with the latest statements from the party," Mustafa said when explaining why he had chosen to speak out.
"I do not know why the party today says I did not fully listen to them when I feel we communicated closely throughout."
He said that Stockholm district chairwoman Veronica Palm coached him through the first days of the media storm and approved everything that he wrote.
"She was a support to me," he said.
"It was with sadness that I chose to answer many of the prejudiced statements. I feel I was very clear with how I viewed women's right, LGBT rights and anti-Semitism."
At Tuesday's press conference, Mustafa went through the accusations he and the associations he was part of faced, including controversial speakers invited to the association's events.
"Salah Sultan and Ragheb Al-Serjany were invited to Islamic Association conferences before I became chairman," he said.
"The people in charge when Sultan came have told me that they did not know he had said that Jews eat bread made with the blood of Christians, which is obviously a very serious anti-Semitic attack used in all ages against Jews."
"Al-Serjany said that Muslims should get their act together and get media savvy like the Jews, which is of course an unfortunate statement because it ties into the conspiracy theory about the Jewish control of the media."
He said that he strongly believed it was only OK to invite such speakers if they repented for their previous statements.
"Such statements can't be allowed to flourish in the media without going unchallenged," Mustafa said.
He also said the claim that the association's bylaws underlined legal differences between men and women were unfounded but admitted such a document had been posted to its website.
"Some young members were translating text from Arabic to Swedish and it went up without being edited. Human error and lack of resources were to blame."
As for a tweet concerning sending Swedish fighter jets to Israel, Mustafa said it appeared logical to him that if Sweden could enforce a no-fly zone over Libya to protect civilians, a similar tactic could be employed to stop human rights abuses in Gaza.
"It stands to reason that we could protect civilians in Gaza," said Mustafa, adding that the tweet contained a link to an al-Jazeera article about Israeli actions in the Gaza Strip.
"I stand by that statement."
"I think the Israeli occupation must be met with a trade boycott and divestment," Mustafa, who came to Sweden as a refugee, said.
He said that he had taken part in many field trips and discussed politics with members of many different groups both in Africa and the Middle East.
"I've spoken to everyone from Christians to the Hezbollah in Lebanon," he said.
"I share some of these people's opinions; with some I do not share their opinions. It is classic Swedish labour movement tradition to take part in debates with people who do not think like you do."
He underscored that he had joined the Social Democrat party the day after the party's 2010 election defeat because as a resident of the suburb of Tensta he felt the opposition party was not diverse enough.
"I didn't see anyone with a refugee background in the party, I didn't see any members who lived in socio-economically vulnerable areas," he said.
"At the same time, on the ground, I saw how the welfare state was being dismantled, how the divide between rich and poor widened and I felt I had to be part of addressing that."