Sweden’s anti-immigration nationalists have said they will back the conservative opposition’s budget proposal over the government’s, putting Prime Minister Stefan Löfven’s political survival in doubt.

Earlier, Löfven had suggested he would resign if his minority government of Social Democrats and Green failed to win parliamentary support for its spending plan.

Right-wing challenge

The conservative and liberal Alliance parties introduced a budget proposal of their own on Tuesday. If the Sweden Democrats do vote with the Alliance, Löfven would be legally obligated to carry out their plans.

Short of stepping down and forcing snap elections — something that hasn’t happened in Sweden since 1958 — the prime minister could send his budget back to committee for amendments in an attempt to win support from centrist parties.

However, the Center Party and the Christian Democrats, who are ideologically closest to Löfven, rebuffed his overtures earlier this year when he tried to lure them into a coalition.

Balance of power

Löfven’s Social Democrats won a plurality of the seats in parliament with 31 percent support in September, forcing the resignation of Alliance leader John Fredrik Reinfeldt.

The Sweden Democrats came in third with almost 13 percent support, giving them the balance of power. All other parties have ruled out cooperating with them.