During the six-hour debate over the bill, Sweden’s foreign minister, Tobias Billström, said he was convinced that the country’s membership would be ratified by Turkey and Hungary, the two hold-outs in the 30-member alliance, before the summit due to be held in Vilnius in the second week of July. 

“It is obvious that we are going to be able to be members at Vilnius,” he said during the debate, pointing to the backing of the other 28 member states and strong support from the US. “The strength that we have behind us is so tangible that it’s possible to come to such a judgement.”

If Sweden were not to be a member before the summer, he continued, it would put Nato’s open-door policy, a key part of its framework, in question. 

Only two of the eight parties in the Swedish parliament voted against the bill, the Left Party and the Green Party, with their MPs providing all of the 37 “no” votes. A further 43 MPs were absent. 

“It is problematic to join a military alliance with countries which are not democratic, and where we see daily that democracy is withering,” said Håkan Svenneling, the Left Party’s foreign policy spokesperson. “They are now trying to use our application to silence our voice on democracy and human rights.” 

The two parties were also critical of the fact that Sweden was now joining an alliance backed by nuclear weapons. 

“The Nato nuclear alliance is built on the idea of using nuclear weapons as a method of deterrence,” said the Green Party’s Jacob Risberg. “The Green Party do not believe in that doctrine, but believe quite the contrary, that this could lead to more conflict.” 

The Social Democrat’s foreign policy spokesperson Morgan Johansson said he was confident that Sweden would not be made to host nuclear weapons on its territory, even though its agreement with Nato contains no formal statement ruling this out. 

The government’s Nato proposition states that “there is no reason to have nuclear weapons or permanent bases on Swedish territory in peacetime”. 

“I feel completely confident in the test which has been drawn up. There is nothing at all pushing for Sweden to be forced to host bases or nuclear weapons,” he said.