The two populist parties that won big electoral upsets in Italy’s national election have close ideological ties to the Kremlin and could shift foreign policy in Italy in favour of the Russian president, Vladimir Putin.

Both the Five Star Movement (M5S) and the League – previously known as the Northern League – have raised the possibility of abandoning Nato, called for ending sanctions on Russia they say have hurt the Italian economy, and have been supportive of Russia’s campaign in Syria.

Previous remarks along these lines were not central to the parties’ election campaigns, but they signal a departure from Italy’s traditionally strong support for Nato and the US.

Matteo Salvini, the head of the League, has made several trips to Moscow, including one visit weeks before the 2016 constitutional referendum he staunchly opposed. The “no” vote ultimately won the contest, marking a major defeat for the then-prime minister, Matteo Renzi, the head of the Democratic party and close ally of former president Barack Obama.

Salvini denied receiving money from the Kremlin after he was asked by journalists in 2014 if the League had received any cash from Russia, as his ideological partner, Marine Le Pen of the National Front, did in France.

“I was in Moscow, not to ask for money, but because we have a political vision of Europe that’s different from today’s, and one that’s not passed by Brussels,” Salvini told journalists in 2014.

Just what that difference means for Italy is not entirely clear.

The M5S’s founder, Beppe Grillo, was once a staunch critic of the Kremlin’s human rights abuses, but the party has shifted its stance in recent years.

In 2016, Manlio Di Stefano, one of the party’s foreign policy experts, gave a speech before a conference of Putin’s United Russia party in which he not only called for an end to EU sanctions, but said it was evident that the “Ukraine crisis” was a result of meddling by the EU and US in Russian affairs.

One expert said that – much like Donald Trump’s support for Russia, which is sometimes at odds with the rest of the US government – the growing influence of the M5S and the League will not necessarily spell a sea change for Italy-Russia relations. But it could signal that more might be up for negotiation, such as Nato’s use of certain bases, resistance to fresh sanctions or renewing previous sanctions, or a demand that Italian troop levels be reduced in the Balkans.

Both parties would be likely to take a more flexible stance on Russian engagement in Libya, and might be more open to negotiations with the Kremlin-backed general Khalifa Haftar, who controls half of the country. The current democratic government has strongly backed Haftar’s rival Fayez Seraj, the head of the government of national accord.

Raffaele Marchetti, a professor at Luiss University in Rome, recalled that at a Russian embassy function last year he could only spot senior politicians present from two parties: the M5S and the League.