Finnish politics could dramatically shift to the far-Right on Sunday as an anti-immigration party aims to replace Sanna Marin's Social Democrats Party.

The 'rock star' prime minister, who took office in 2019 as the world's youngest PM at 34, has become one of Finland's most popular leaders, polls show.

However, latest figures put the mother-of-one's centre-Left SDP in third place behind the anti-immigration and nationalist Finns Party and the centre-Right National Coalition Party, which held on to a thin lead.

'It is a very exciting situation and it's hard to say at the moment which party will be the biggest on election day,' Tuomo Turja of the polling firm Taloustutkimus told AFP.

A win for the far-Right Finns Party, and a far-Right prime minister, would be a first in Finland - but the party has previously served in government in a coalition. It currently looks set to top its record 19 per cent from the 2011 election.

Traditionally, the biggest of the eight main parties in parliament claims the top post and tries to build a government.

Marin leads a centre-Left coalition of Social Democrats, the Centre, the Greens, the Left Alliance and the Swedish People's Party of Finland.

Although some view her as a strong leader who skillfully navigated the Covid-19 pandemic and the country's NATO membership process, others say her partying scandals and youthful behaviour make her unfit for office.