The country’s Conservative prime minister, Erna Solberg, said she would continue with a minority government comprised of three coalition parties, including the centrist Liberal Party and the Christian Democrats.
She said “the cup is now full” after a 29-year-old Norwegian woman of Pakistani descent arrived in the country on Saturday with her two children.
The woman, who had reportedly travelled to Syria in 2013 and married a Norwegian foreign fighter, who was later killed in fighting, was formally arrested on her return and placed in a hospital in Oslo with both children.
One of the woman’s children was said to be quite ill and a government announcement explained she received help to return to Norway from Syria so the child could get medical treatment.
Ms Solberg said she “understood” why the Progress Party wanted to leave her coalition government and she would seek cooperation with the party, which is Norway’s third largest.
The exit of the Progress Party means Ms Solberg no longer has a parliamentary majority, which could make it harder for the coalition to govern the country.
Norway’s next parliamentary election is scheduled for September next year, and Ms Solberg will need the support of parties outside the government to stay in office and pass legislation in the 169-seat parliament.
Ms Jensen said many believed the mother “used her child as a shield to come back to Norway”.
“There are many ... who are displeased by this, not just in the Progress Party,” she said last week.
The mother, who has not been named, refused to let her sick child travel alone to Norway, which then allowed her to travel from the Kurdish-controlled camp at al-Hol, where the family had been detained since March last year.
She has denied the charges against her and will fully cooperate with the police during interrogation, her lawyer has said.
“A majority in the government believed that concern for the child was paramount,” Ms Solberg said.
Decisions about whether to help women with ties to Isis return from Syria have caused controversy across Europe. In Finland, the recently appointed government settled on a compromise to decide each case individually.
Additional reporting by agencies