Paris (CNN) As France's presidential candidates gathered for the final debate in an already tumultuous election campaign, the sound of gunfire rang out on the streets of Paris once again.

Thursday's terror attack on the Champs-Elysées, in which a policeman was killed and others wounded, just days before the country goes to the polls has brought yet another twist to an increasingly unpredictable election race.

But the notion that the attack could effectively hand the election to Marine Le Pen, who has taken a hardline stance on terrorism and called for France to close its borders, is misplaced, according to Emmanuelle Schön-Quinlivan, lecturer in European politics at University College, Cork.

On Friday, French Prime Minister Bernard Cazeneuve accused Le Pen, leader of the far-right National Front Party, of trying to make political capital out of the attack.

"The candidate from the National Front, like every drama, seeks to profit and use the situation to divide and benefit for exclusively political ends," Cazeneuve told reporters.

French media report that the suspect in the case, named by the Paris prosecutor's office as Karim Cheurfi, was on the radar of intelligence services before the attack.

But a spokeswoman for the Paris prosecutor, Agnes Thibault Lecuivre, said he was not on the official "Fiche S" surveillance list, which tracks individuals suspected of being radicalized.

Le Pen has previously called on the government "to expel foreign imams who preach the hate and fundamentalism of foreign Fiche S."

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'Real statesman'

Schön-Quinlivan thinks Republican candidate Francois Fillon, whose campaign has been beset by scandal, could gain votes in Sunday's first round.

"Fillon comes across as calm and a real statesman and reassures people," she told CNN.

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"In contrast Le Pen, who has strong and radical ideas against radical Islam, often comes over as angry and aggressive.

"She doesn't reassure the electorate. Fillon has past experience as prime minister which gives the him the kind of composure which reassures people."

Fillon, an early favorite for the presidency, has trailed in the polls since becoming embroiled in a parliamentary scandal over claims he paid his wife and children for work they did not do.

He was placed under formal investigation on multiple counts, including embezzlement of public funds , but refused to stand aside.

"A lot of people are put off by this," said Schön-Quinlivan. "You have people who are trying to make ends of meet and wanting to improve the standard of living for their children. They don't want to vote for someone who takes public money to pay for their own family.

"There are a majority of people who can't stand that old politics," she said. "It comes down to whether people feel that the the attacks are more important, or do we put the scandals aside?"

"I think the latter will prevail," she added. "It's not our first attack and people are more focused on their personal [issues]."

Impact on Macron

While Fillon may have experience on his side, it is the youthful Emmanuel Macron who had been widely expected to make it through to the runoff on May 7.

In the wake of the attack, Macron urged voters: "Do not to give in to fear, do not to give in to division, do not to give in to intimidation."

The independent centrist said he would hire an additional 10,000 policemen over the next five years.

But questions remain over his experience and the fact he is competing without the support of a traditional political party.

Macron, a former economy minister and investment banker, has promoted his campaign as the future of France.

It is a future which Schön-Quinlivan believes France is likely to embrace.

"If this had been the first attack, it might have had an impact," she said. "But we've had so many attacks and we're too close to election now."

"I don't think this will affect the result fundamentally and if Macron gets through to the next round then he is expected to beat all his rivals," she added.

"Yes, he's not experienced, but he will be surrounded by experts," she said. "He's very well educated and will do politics differently."

Turnout boost?

Thursday's attack is not the first terror-related incident to mar this French election cycle; prior attacks in the country -- from the 2015 Paris attacks to last year's Bastille Day attack in Nice -- remain embedded in the national psyche.

But whether many voters will be discouraged from turning out to vote in the face of another potential attack remains to be seen.

CNN's Cyril Vanier believes the campaign has been so polarizing -- and the stakes so high -- that the electorate will want their voices to be heard.

But, if a significant number stay home, this could benefit Marine Le Pen.

"The consensus is [she] would benefit from a lower turnout," Vanier said. "Her voters are more energized, a lot of them are sure of their choice."

What now?

With just two days to go before voting gets underway in the French presidential election, polls suggest the race is simply too close to call.

Eleven candidates are standing in the first round, although only four have a serious chance of winning.

Le Pen and Macron had been widely tipped to make it through to the second round of voting on May 7, but Fillon and left-wing firebrand Jean-Luc Mélenchon have closed the gap in recent weeks.

Support for Mélenchon has surged following his impressive performances in the presidential television debates.

Polls open at 8 a.m. local (2 a.m. ET) on Sunday; they close at 7 p.m. (1 p.m. ET) in rural areas and small towns with voting stations staying open an hour later in cities and larger towns.

Early results are expected to follow soon after polls close.

Correction: This story has been updated to clarify the extent to which French intelligence authorities were monitoring Karim Cheurfi before the attack.