Italy appears set for fresh elections that could push the country further toward the far right.

Matteo Salvini, the deputy prime minister, reiterated his calls for a snap vote on Friday, adding that any attempt to block his wishes and install a new ruling coalition would be unacceptable. His League party said it would present a no-confidence motion in the senate in its push to dismantle the tempestuous coalition with the anti-establishment Five Star Movement (M5S).

The developments follow Salvini’s demand for the prime minister, Giuseppe Conte, to reconvene parliament to collapse the administration.

Salvini has already announced his candidacy to be the next prime minister, even though elections are yet to be scheduled. “Give us the strength to take this country in hand and save it,” he told supporters during a rally in the coastal city of Pescara on Thursday night.

Backing for the League has flourished over the past year, with recent polls putting it at 39%, while support for M5S has halved to 15%.

Salvini said his party would run for elections alone, and if it fell short of the 40% majority required to govern it would “choose a travel companion”. The most likely partner is seen as the Brothers of Italy, a party with a neo-fascist lineage that together with the League would create a fully far-right government in a major western European nation.

Giorgia Meloni, the Brothers of Italy leader, said new elections could bring about a government set on making the “politically incorrect reforms that Italy needs”.

Both Salvini and Meloni have whipped up support with their anti-immigrant, “Italians first” rhetoric, and by attacking Pope Francis and his calls to help migrants. The pontiff expressed his concerns over nationalism in an interview with La Stampa on Friday.

“I am concerned because we hear speeches that resemble those of Hitler in 1934. ‘Us first, We … We … ’ These are frightening thoughts,” he said.

Salvini’s political ascent has been aided by his relentless campaigning, using social media and rallying on piazzas and beaches across the country with what he presents as a ‘man of the people’ style and a defence of Italian ‘identity’. His demonising of a succession of so-called enemies – migrants, Roma people, Muslims, leftwing ‘do-gooders’ – has also formed a reliable component of his success.

The political turmoil caused European stock markets to fall as they opened on Friday, with Milan’s exchange dropping 2.3%.

The rift between the League and M5S widened on Wednesday when parliament rejected a motion by M5S to block a high-speed rail project linking Italy and France. M5S has built most of its popularity on vehemently opposing the long-stalled project but was outvoted by the League and opposition parties.

The League’s motion said “too many no’s are bad for Italy” and that “those who waste time, harm the country”.

Conte, who does not belong to either party, reacted angrily to Salvini’s demands. “This government wasn’t at the beach but working from morning until night,” he said late on Thursday, referring to Salvini’s seaside escapade last week.

Conte, who had held separate talks with Salvini and the country’s president, Sergio Mattarella, said it was not up to the deputy prime minister to summon parliament and “dictate the steps of the political crisis”.

The decision to dissolve the government and call new elections rests with Mattarella. He could also choose to install a technical government in order to pass the 2020 budget in the autumn, but that option is unpopular with all parties.

Luigi Di Maio, the M5S leader and co-deputy prime minister, said he was ready to return to the polls as “the League has mocked Italians”. Nicola Zingaretti, who heads the centre-left Democratic party, said elections were the only option.

Francesco Galietti, the founder of the Rome-based political consultancy Policy Sonar, said: “The crisis is now a fully fledged one and nobody, not even Mattarella, can put the genie back in the bottle.

“The reality is that Salvini caught everyone by surprise, even his own people, but by doing so he’s cornered Mattarella into a very nasty position.”

Parliament could be reconvened by 20 August to confirm the end of the administration. Elections would then have to be held within 50 to 70 days.