PARIS (AP) — Roads blocked, oil refineries disrupted, planes grounded and trains halted — unions are threatening to shut down France’s economy this week in what they hope is their toughest riposte yet to President Emmanuel Macron’s plan to raise the retirement age.

The first actions are expected Monday, as truckers are being urged to block major highway arteries and interchanges in go-slow actions dubbed ’’escargot” operations. Unions plan an open-ended strike on the national rail service starting Monday evening.

The government is bracing for the biggest disruptions Tuesday, when strikes are expected across multiple sectors and protests are planned in cities across France against the retirement bill. The reform, which would raise the official pension age from 62 to 64 and require 43 years of work to earn a full pension, is currently under debate in parliament.

“There will be a very strong impact” from the strikes, Transport Minister Clement Beaune said on regional broadcaster France-3 on Sunday. “I know that for many people it will be a real headache.”

Labor Minister Olivier Dussopt, speaking on the FranceInfo news broadcaster on Monday, said “expressing disagreement is legitimate, yet it must not lead to blocking the country, which would be dangerous to our economy.”

Authorities encouraged people to work from home on Tuesday if possible.

The complex pension bill is a centrepiece of Macron’s presidency and his efforts to keep the French economy globally competitive. The centrist, business-friendly government says it’s needed to keep the pension system solvent as the population ages and fertility rate drops.

Opponents, which opinion polls suggest include a majority of French voters, say the changes threaten hard-fought French rights. Left-wing lawmakers say companies and the wealthy should pitch in more to keep the system afloat instead.

The draft law has prompted the liveliest debate in years in the French parliament.

It is currently under discussion in the conservative-led Senate. The bill is expected to be voted on by the end of the week at the upper house of parliament, where The Republicans said they would vote alongside Macron’s centrist allies to raise the retirement age.

France’s civil aviation authority asked airlines to cancel 20 per cent of flights at Paris’ Charles de Gaulle Airport on Tuesday and 30% of flights at Orly Airport, in addition to cancellations in other cities. Trains to Germany and Spain are expected to come to a halt Tuesday, and those to and from Britain will be reduced by a third, according to the SNCF rail authority.

The hard-left CGT union is also calling for strikes Tuesday at factories making Renault, Peugeot and Citroen cars, Airbus planes and other sites. Dockers’ unions are threatening to block ports on Wednesday.

The head of the more moderate CFDT union, Laurent Berger, called for a “very powerful action day” on Tuesday involving “many, many people in the streets.” He said that more than 250 demonstrations will be organised across France. Unions will then hold a meeting to decide about the next steps of the mobilisation, he added.

Unions have rallied some of France’s biggest protests in decades since the bill was introduced in January, but this week is shaping up as especially challenging.

Protest actions focused on women — and the retirement reform’s impact on working mothers – are expected Wednesday, to coincide with International Women’s Day.

And on Thursday, unions representing students who haven’t even entered the workforce yet are seeking to mobilise young people to take to the streets to share concerns about retirement rights.

While the measure has a good chance of winning eventual Senate approval, unions hope that strikes and protests this week will keep up pressure on the government to make concessions, as the bill is to continue its way through the complex legislative process.