France's Senate voted Thursday to raise the retirement age by two years to 64, as the government moves to overhaul the country's pensions system in the face of strong opposition from labour unions.

The conservative-dominated legislative body voted in favour of a decisive article to raise the age of retirement by 201 votes to 115.

Debate will resume later on Thursday over a controversial amendment to the bill.

The Senate majority is rushing to meet a deadline of midnight Sunday to finalise the legislation.

Liberal politicians voiced anger following the vote.

"Your name will forever be attached to a reform that will set the clock back almost 40 years," Socialist Monique Lubin told Labour Minister Olivier Dussopt.

Labour unions have vowed to pile pressure on the government by staging protests and strikes.

On Wednesday, fuel deliveries, trains and flights were disrupted for a second day following mass rallies.

Key sea ports were also blockaded, as dock workers were among those to join rolling strikes seeking to convince President Emmanuel Macron to reverse course on the bill he has championed.

Macron has put the change at the centre of his political agenda, with his government arguing that raising the retirement age and stiffening the requirements for a full pension are essential to keeping the system from sinking into deficit.

France lags behind most of its European neighbours, which have hiked the retirement age to 65 or above.