Emmanuel Macron has vowed to intensify his overhaul of France’s welfare state, tax system and labour market if he wins a second term as president next month, arguing that transforming French society would protect people at a time of crisis when the war in Ukraine marks “a return of tragedy in history”.

The 44-year-old centrist leader has risen in the polls since Russia’s invasion and is a clear favourite to win April’s election – which would make him the first French president to win re-election in 20 years. But he has been under pressure from opponents to explain his economic and social policy.

“We are at a tipping point where we can make a real difference,” Macron said during a four-hour press conference at a former warehouse in the northern suburbs of Paris, warning of a mix of global crises including Ukraine, the Covid pandemic, climate change and the challenges of self-sufficiency in farming.

Macron vowed to step up his changes to the welfare state and the benefits system, raising the pension age and continuing to cut taxes for businesses and households. Brushing aside the potential for widespread street demonstrations, he said people must “work longer” in order to protect France’s generous pensions system.

Although Macron has been boosted by his stature on the international scene, voters are struggling with a cost-of-living crisis and pollsters fear abstention could be significant if the election is seen as a foregone conclusion.

Macron said that if re-elected he would move swiftly to carry out the pensions overhaul that he had failed to put in place in his current mandate. He would gradually increase the pension age from 62 to 65, bringing it into line with countries such as the UK and Germany, while setting a minimum pension rate at €1,100 a month. He said he had “learned the lessons” from his past difficulties.

In 2019, Macron’s proposed pensions overhaul sparked protests that lasted longer than any strike since the wildcat workers’ stoppages of 1968, and the measures were shelved during the pandemic.

Macron said he would also radically overhaul the unemployment benefits system to push people back to work. This would include requiring unemployed people to undertake 15 to 20 hours of work or training a week. In another politically risky change, all social benefits – for unemployment, housing or childcare – would be centralised in a single system, affecting up to 20 million people.

“It’s quite normal, especially when you consider the state of public coffers, that we work more,” he said.

Macron has gained five to six points in opinion polls over the past month, and is well ahead of the far-right Marine Le Pen, who is currently in second place. He is favourite to win the first round on 10 April by a wide margin. But it is not clear which candidate will face him in the final round on 24 April.

Le Pen is being trailed in the polls by three candidates: the rightwing challenger Valérie Pécresse, the far-right former TV pundit Éric Zemmour and the hard-left Jean-Luc Mélenchon, whose campaign is gaining momentum. Polls show Macron beating all of them.

Despite that, Macron remains a divisive figure in France. When he came to power five years ago he was a former banker who had served as economy minister under the left and promised a new kind of “pragmatic” centrist politics that he said would liberalise the economy. He loosened strict labour laws, but his pro-business moves – cutting corporate taxes and transforming the wealth tax into a property tax – swiftly led to him being labelled “president of the rich”, a tag he has struggled to shake off.

His reform programme was hit by two major crises. First, the gilets jaunes protest movement over fuel prices that turned into an anti-government revolt. Then the Covid pandemic, which has killed more than 138,000 people in France and exposed strains on the health service. In response, Macron turned to state interventionism and vast public spending. He boasted of “nationalising wages” to keep the country afloat.

Macron now faces accusations from critics including Gérard Larcher, the rightwing head of the senate, that he could be re-elected too easily. Larcher said Macron could win re-election “without ever really having been a candidate, without a campaign, without a debate, without a competition between ideas”, leaving questions over his mandate to govern during a second term.

Macron angrily brushed aside Larcher’s comments and stood by his record in office. “I promised lower unemployment … despite the crises, we did it,” he said, adding that if re-elected his aim was to wipe out unemployment entirely.

He also said France could be one of the first countries to wean itself off fossil fuels, and he wanted to build a “European metaverse” to compete with US tech firms and make Europe more independent. He promised greater protection for children online by increasing regulation of social networks, and a consultation on changes to the education and health systems.