Public sector unions in France on Tuesday embarked on a nationwide strike calling for higher salaries in response to soaring inflation.

The walkouts pose one of the toughest challenges to French President Emmanuel Macron since he was re-elected in May.

What is affected by the strike?

The latest action involves public sector unions and affects services such as transport. It comes after weeks of action at major oil refineries that put supply to the country's gasoline stations in jeopardy.

Cross-English Channel operator Eurostar said it was canceling some trains between London and Paris because of the action.

French news agency AFP reported that the effects of the strike were visible at the Paris hub Gare de Lyon.

Meanwhile, French public railway SNCF said local connection traffic was down by some 50% but that national lines were not experiencing disruption.

Civil service workers' unions are also urging workers to join in on Tuesday's strike, with possible walkouts in schools and other public facilities.

At the same time, the CGT trade union confederation called for walkouts to extend into a fourth week at refineries and fuel depots operated by energy giant TotalEnergies.

The plea came despite the oil company reaching a deal that included a 7% increase and a bonus with other unions. The CGT is demanding a 10% pay rise, pointing to the firm's huge profits and the backdrop of inflation.

The government has used requisitioning powers to force some strikers back to open depots. Although the move has infuriated unions, it has so far been upheld in court.

The strike by fuel workers has severely hit fuel distribution across France, particularly in northern and central regions, including Paris.

Strikes have also spilled over into other parts of the energy sector, including nuclear giant EDF, affecting maintenance work that is crucial for a wider European power network.

Testing times for Macron's government

The strikes come against a tense political background as the government of French President Emmanuel Macron is set to pass the 2023 budget using special constitutional powers.

Macron, whose government is on the defensive after losing its majority in legislative elections, is seeking to push through his key policy of raising the French retirement age.

Thousands of protesters converged on Paris on Sunday to protest rising prices.

Jean-Luc Melenchon, the leader of the hard-left France Unbowed party, marched alongside this year's Nobel Prize winner for Literature, Annie Ernaux. Melenchon urged a general strike on Tuesday.