French schools, trains and businesses are set to be affected Thursday by the first major strike called since the re-election of President Emmanuel Macron in April, as unions push for wage hikes and the end of planned pension reform.

File photo: AFP

The extent of disruption remains uncertain, however, with the strike a test for the CGT union behind the protests, which is seeking to build support for a lengthy battle with the centrist government.

Macron has approved wage hikes for civil servants and teachers and put in place one of Europe's most generous anti-inflation safety nets that has capped energy prices for households and held down inflation.

But his insistence on raising the retirement age from its current level of 62 -- one of his main re-election campaign pledges -- has stirred up unions and other left-wing opponents and remains broadly unpopular around the country.

"We are against pushing back the age of retirement because we consider it an aberration when there are so many unemployed people in this country," Philippe Martinez, the head of the CGT, told the BFM broadcaster on Tuesday.

"Keeping people with work in their work means that people who haven't got any can't find it," he added.

Despite warnings from allies about the risk of failure, Macron has tasked his government with hiking the retirement age from the current age of 62, one of the lowest in Europe, with changes set to take effect next year.

With deficits spiralling and public debt at historic highs, the former investment banker has argued that pushing back pensions and getting more people into jobs are the only ways the state can raise revenue without increasing taxes.

His centrist party lost its majority in parliament in June, severely undermining his ability to push through changes.

"If the president insists on declaring a social war on the people, we will respond with all the means at our disposal," the parliamentary leader of the France Unbowed (LFI) political party, Mathilde Panot, tweeted on Wednesday.