With 10 days to go before the runoff of a presidential election that pits far-right leader Marine Le Pen against incumbent Emmanuel Macron, the student protests are another sign that the president can no longer count on voters rejecting the far-right en masse.

At the Sorbonne, the epicentre of many French student revolts over the years including the May 1968 uprising, a few hundred gathered on its front square in Paris's Latin quarter.

"We're tired of always having to vote for the less bad of the two, and that's what explains this revolt. Neither Macron nor Le Pen," Anais Jacquemars, a 20-year old philosophy student at the Sorbonne, told Reuters.

All the left-wing candidates were eliminated in the first round of the election on April 10. Many of the students said they'd rather abstain in the runoff than put a Macron vote in the ballot box to block Le Pen from winning power.

Some said Macron's policies during his first term in power had veered too much to the right, citing police brutality against Yellow Vest protesters or measures to crack down on what Macron calls "Islamist separatism".

"I'm planning to abstain, I advise everyone to abstain," said Gabriel Vergne, a 19-year old student at the elite Sciences-Po school of government. He voted in the first round for left-wing firebrand Jean-Luc Melenchon, who missed the runoff by just 400,000 votes.

"I think the fight no longer lies in the ballot box. Today, this election has been largely discredited ... so it has become necessary to bring the fight to other fronts," Vergne said, calling for strikes with workers' unions.

The rejection by left-wing voters of the so-called "republican front", whereby French voters traditionally rally behind the mainstream candidate facing a far right contender, is a growing concern in Macron's camp.

Opinion polls show the race between the two candidates is extremely tight, with Macron leading by a 5- to 10-point margin over Le Pen, sometimes within the margin of error and meaning a Le Pen victory is not impossible.

Students calling on voters to abstain in this election are in stark contrast with the situation two decades ago, when Jean-Marie Le Pen, founder of the far right National Front and Marine Le Pen's father, faced then President Jacques Chirac in the 2002 election runoff.

Mass demonstrations were seen across France as students voiced anger at Jean-Marie Le Pen's surprise qualification for the final round and urged French people to vote for Chirac, a conservative, who ended up winning with over 82% of the vote against Le Pen.

The National Front has since been renamed the National Rally under Marine Le Pen.

"Today, the National Front is in the second round and is very, very close to winning, and people are protesting a lot more against Macron than against the National Front," Alexis, 23, another philosophy student at the Sorbonne, said.

"I think that's terrible, I think it's a failure because it contributes to the normalisation of the ideas of the National Front," he added, declining to say who he will be voting for.