PARIS (AFP) - French President Emmanuel Macron pledged further tax cuts, reforms to the welfare system and major public investments on Thursday (March 17) as he unveiled his manifesto less than a month from elections.

The 44-year-old had delayed confirming his intention to seek a second term till March 3 and has been at the heart of Western diplomatic efforts to halt Russia's invasion of Ukraine.

Speaking at his first major campaign event in Paris, he announced a programme aimed at deepening pro-business reforms started in 2017 to reduce chronically high unemployment.

"We have to work more," Macron told some 300 journalists gathered at a venue in a northern Paris suburb, in front of giant screens showing his slogan "With You".

"We have two levers: full employment and reforming the pension system," he said.

Macron acknowledged that he had been unable to push through the pension overhaul as promised in 2017, but pledged to tackle it again and push back the retirement age to 65 from 62.

He also proposed reforms to the benefits system that would require the unemployed to undertake 15 to 20 hours of work or training per week.

Another politically risky change would see all social benefits - for unemployment, housing, or childcare - centralised in a single system, affecting up to 20 million French people.

Major new public investments in the health and education systems, as well as in the military and new technologies, would total €50 billion (S$75 billion) a year, he said.

Question of 'legitimacy'

Rivals across the political spectrum, who have struggled to make an impact as Russia's invasion of Ukraine has dominated headlines, have accused Macron of neglecting the election campaign until now.

He has taken a leading role in Western diplomatic efforts to stop the war in Ukraine, holding 20 hours of talks with Russian leader Vladimir Putin in the last five weeks.

"The president wants to be re-elected without ever really having been a candidate, without a campaign, without a debate, without a competition of ideas," the head of the Senate, Gerard Larcher, said on Tuesday.

"If there isn't a campaign, then there will be questions about the legitimacy of the winner," Larcher, from the opposition Republicans party, told Le Figaro newspaper.

In the most recent voter surveys he has gained five to six points over the last month and could be on course to win the first round of the election on April 10 with a score of about 30 per cent.

Veteran far-right leader Marine Le Pen is running in second place, on around 18 per cent, a poll of polls by the Politico website suggests.

She is trailed by three candidates at around 11-12 per cent - right-wing challenger Valerie Pecresse, far-right former TV pundit Eric Zemmour and hard-left campaigner Jean-Luc Melenchon, who appears to be gaining momentum.

The top two candidates in the first round will progress to a run-off vote on April 24.

Polls suggest Macron will triumph by a large margin irrespective of his rival.

Behind the scenes, the president is reported to be urging ministers and campaign workers to guard against premature optimism - to limited effect.

"Macron is winning by default. It's the others who are useless," one senior supporter told AFP this week, likening the incumbent's opponents to "dwarves".

The head of state remains a highly divisive figure, dubbed the "president of the rich" by left-wing critics and criticised for his at-times abrasive personality.

He faced violent anti-government demonstrations in 2018 by so-called Yellow Vest protesters.

One wildcard in the election outcome could be voter turnout, with a survey by the Odoxa polling group, published by Le Figaro on Wednesday, suggesting one in four people might abstain in the first round of the election, the second-highest rate since 1965.