The party of far-right leader Marine Le Pen will top the upcoming European Parliament elections with 22 percent of the vote, just ahead of President Emmanuel Macron's REM party, an Ipsos poll released on Sunday.
It was the first time Le Pen's Rassemblement National (RN) - formerly the National Front - overtook Macron's REM in an Ipsos survey ahead of the EU election this year, although other, daily polls have shown the RN in pole position before.
EU elections will be held on May 26 in France.
The poll of 1,500 people was conducted on May 2-3, after Macron announced a series of proposals, including tax cuts worth 5 billion euros ($5.6 billion), in a bid to appease the "yellow vests" anti-government protest movement.
Macron's REM party would obtain 21.5 percent of the vote, the Ipsos poll for France Television and Radio France showed. On April 18-22, 23 percent of the people polled said they would vote for REM, against 22 percent for RN.
Macron is facing the biggest challenge of his presidency yet in the "yellow vest" protests, which started nearly six months ago over the high cost of living but spread into a broader movement against the former investment banker's pro-business reform drive.
Dissatisfaction over slow economic growth, security threats posed by Islamist militants and a backlash against migration across open EU borders have boosted support for nationalists in many member states.
The RN and other eurosceptic anti-immigration parties in other EU states are planning to join forces after the EU parliamentary election.
(Reporting by Sybille de La Hamaide)