PARIS - Protesters clashed with police in central Paris as demonstrations were held against Marine Le Pen’s far-right National Rally (RN), which jumped into an early lead in France’s snap election.

Thousands of people gathered in the Place de la Republique as first-round legislative elections on Sunday plunged the country into political uncertainty.

Video showed fireworks being set off in the direction of police who responded by firing tear gas, while windows were smashed in the chaos.

Barricades designed to keep crowds under control were torched as protesters vented their anger.

The anti-immigration party led by Ms Le Pen scored historic gains in Sunday’s vote, exit polls showed, but the final result will depend on days of horsetrading before next week's run-off.

The nationalist party was seen winning around 34% of the vote, exit polls from Ipsos, Ifop, OpinionWay and Elabe showed, in a huge setback for President Emmanuel Macron who had called the snap election after his ticket was trounced by RN in European Parliament elections earlier this month.

RN's share of the vote was comfortably ahead of leftist and centrist rivals, including Mr Macron's Together alliance, whose bloc was seen winning 20.5%-23%. The New Popular Front (NFP), a hastily assembled left-wing coalition, was projected to win around 29% of the vote, the exit polls showed.

The exit polls were in line with opinion surveys ahead of the election, and were met with jubilation by Ms Le Pen's supporters. However, they provided little clarity on whether the eurosceptic RN will be able to form a government to "cohabit" with the pro-EU Mr Macron after next Sunday's run-off.

At Ms Le Pen's Henin-Beaumont constituency in northern France, supporters waved French flags and sung the Marseillaise.

"The French have shown their willingness to turn the page on a contemptuous and corrosive power," she told the cheering crowd.

RN's chances of winning power next week will depend on the political dealmaking made by its rivals over the coming days. In the past, centre-right and centre-left parties have teamed up to keep the RN from power, but that dynamic, known as the "republican front," is less certain than ever.

If no candidate reaches 50% in the first round, the top two contenders automatically qualify for the second round, as well as all those with 12.5% of registered voters. In the run-off, whoever wins the most votes take the constituency.

Mr Macron called on voters to rally behind candidates who are "clearly republican and democratic", which, based on his recent declarations, would exclude candidates from the RN and from the hard-left France Unbowed (LFI) party.

Political leaders from the centre-left and far-left all called on their third-placed candidates to drop out.

"Our guideline is simple and clear: not a single more vote for the National Rally," France Unbowed leader Jean-Luc Melenchon said.

However, the centre-right Republicans party, which split ahead of the vote with a small number of its lawmakers joining the RN, gave no guidance.