The last polls published before the pre-election media blackout showed the anti-immigrant League neck-and-neck with the centre-left Democratic Party.
Italy's fragile governing coalition is bracing for a key regional election this weekend which the far-right League hopes will trigger a political earthquake and return strongman Matteo Salvini to power.
The wealthy centre-north region of Emilia Romagna was once the Italian left's fiefdom, but while left-wing values still hold sway under the graceful porticoes of its cities, the right is making serious inroads in the villages and towns beyond.
The last polls published before the pre-election media blackout showed the anti-immigrant League neck-and-neck with the centre-left Democratic Party (PD), which governs Italy in coalition with the anti-establishment Five Star Movement (M5S).
International markets will be watching closely for potential seismic change in the eurozone's third-argest economy.
Sunday's vote "is a big test for the beleaguered coalition", said Berenberg economist Florian Hense.
"A PD defeat could possibly be the straw that breaks the camel's back and spell the end of the coalition," he said.
The coalition's main stabilising factor is a joint fear of snap elections which could hand power to Salvini.
'Risk of implosion'
Prime Minister Giuseppe Conte has dismissed fears of a government crisis should the League triumph in Emilia Romagna, saying the election concerns the region alone and has no bearing on national politics.
But a League victory would increase coalition tensions considerably, with the PD likely to blame the M5S for refusing to join forces behind a single candidate thus splitting the anti-Salvini vote.
Analysts have warned it could cause the M5S, which is riven by infighting and has been haemorrhaging members, to collapse.
"A defeat in Emilia Romagna could speed up their implosion, and if the government loses its majority at the Senate, it would be difficult to survive," said Lorenzo Codogno, former chief economist at the Italian Treasury Department.
In a bid to stave off a crisis, M5S head Luigi Di Maio, heavily criticised by a growing number of party members, bowed to pressure and stepped down Wednesday as a leader.
On Thursday, Conte cancelled his appearance at the World Economic Forum in Davos, Switzerland, "to attend to urgent government business".
Salvini meanwhile was confidently predicting victory in the Parma ham and Parmesan cheese heartland, posting pictures of steaming plates of the region's tortellini pasta on Twitter, along with snaps of him canvassing in red-roofed towns
Salvini vs Sardines
The region is the second richest in Italy, with some of the lowest jobless figures in the country and home to "Made in Italy" success stories such as Ferrari.
But analysts say it also boasts many family-run, artisanal firms that have come under pressure from the march of globalisation.
The League leader is determined to return to power.
His party had been governing in coalition with the M5S last year when he pulled the plugin a failed attempt to spark elections and rule Italy alone.
As he held his final pre-vote rally on Thursday, a boisterous counter-demonstration was being held by the youth-driven Sardines movement, which has become a symbol of protest against the far-right firebrand.
The movement sprang up just two months ago in the region's historic capital Bologna when a rally organised by four unknown activists to denounce Salvini's discourse of "hatred and division" unexpectedly drew a crowd of 15,000.
Sunday's vote is being seen by many as pitting Salvini versus the Sardines.
The League leader has fuelled this narrative by dominating his party's campaign, largely overshadowing its candidate Lucia Borgonzoni, 43, whose name does not even feature on election posters.
That has exasperated the PD, whose candidate Stefano Bonaccini is the incumbent Emilia Romagna president, and is hoping to win on the back of local success stories that risk being eclipsed by a Salvini-Sardine showdown.