French President Emmanuel Macron's government is trying to revive his economic reform drive and score a major political victory this week by launching a pension reform in the face of fierce union opposition.

French Prime Minister Elisabeth Bourne will tomorrow set out details of plans to likely raise France's retirement age to 64 or 65 from 62.

Passing the reform through the Parliament, according to French media, will not be easy. Macron lacks a majority and would have to win over several dozen conservative MPs or use constitutional powers to bypass the Assembly, which would anger the opposition.

With one of the lowest retirement ages in the world's industrialized countries, France spends more than most other countries on pensions, nearly 14 percent of economic output, according to data from the Organization for Economic Co-operation and Development.

Pension reform in France, where the right to a full pension is acquired from the age of 62, has always been a sensitive topic, especially now with growing discontent over the rising cost of living.

The government states that the reform is necessary to ensure the funding of pensions in the coming years.

The goal is to strike a balance without raising taxes or cutting pensions. There are various options on the table, but they all involve raising the retirement age, French government spokesman Olivier Verand said.