Romania’s election in early May could prove to be a significant litmus test to determine the extent of Russian influence within Europe. The country is set to head to the polls on 4 May in a rerun of an election held in November which was annulled due to Russian interference.

Late last year, fringe far-right candidate Calin Georgescu, a well-known admirer of Vladimir Putin, stormed from political obscurity to victory in the country’s first round of elections. But the election was cancelled by the country’s constitutional court over concerns that his online campaign had been boosted by Russia in an attempt to install a favourable leadership regime into power. Declassified documents released by Romania’s top security council in the aftermath showed the country had been targeted by “aggressive hybrid Russian attacks” during the election period.

Georgescu has since been disqualified from running but his replacement George Simion, leader of the far-right Alliance for the Union of Romanians (AUR), has since stormed into a lead in the polls which has concerns rising throughout Brussels.

According to polls, around 40% of voters remain undecided, leaving plenty of room for campaigning but also for potential interference.

Four candidates have a realistic chance of proving successful in May’s election, with Crin Antonescu, the governing party’s candidate, centrist independent Nicușor Dan and left leaning nationalist Victor Ponta all also in the running.

Each of the candidates have polled second at various points behind Simion although those same polls failed to predict a Georgescu victory in November’s initial election.

Romania gained European membership in 2007 and has committed to adopting the Euro in the near future, but the outcome of the election looks set to be a watershed moment for the country’s relationship with the west.

As a member of NATO, the election of a candidate likely to take a softer approach to Russia has significant impact beyond Europe as the defensive alliance struggles some form of cohesion.

Simion has in the past been subjected to claims that he has met with Russian spies, something he denies, but the potential future leader of a NATO member is currently banned from entering Ukraine and Moldova due to his calls for land to be reclaimed.

The AUR leader has attempted to distance himself from his pro-Russian reputation, recently labelling Putin as a great threat.

But he is well-known to be against providing Ukraine with further assistance and the potential election of another NATO ally and EU leader with Russian sympathies is likely to be causing great deal of unease across dozens of western capitals.