The nationwide strike that paralyzed Belgium's transport network on Monday highlighted growing opposition to proposed pension reforms, as labor unions mobilized an estimated 30,000 workers from across multiple sectors.

The action brought air and rail services to a standstill and forced numerous schools to close their doors.

In the Belgian capital, Brussels airport reported that nearly 50 percent of its flights were grounded after crew, including luggage handlers and security personnel, joined the walkout, and the national railway company NMBS operated only skeleton services across the country.

The Brussels Times newspaper reported that protesters filled the capital's central streets, with strong participation from the education sector, transport workers, prison employees, and military personnel.

The pension reform controversy has become a major sticking point in ongoing talks around the forming of Belgium's next government, which have stalled since the June 2024 elections, with five negotiating parties, known as the Arizona coalition, unable to bridge their differences over fiscal policy and pension system changes.

Union leaders have rejected the pension proposals under discussion by the Arizona negotiators, warning that the reforms would lead to reduced benefits, stricter eligibility requirements, and extended working years.

The education sector's mobilization was significant nationwide, forcing numerous schools to close as an estimated 25,000 teachers, mostly from the northern region of Flanders, converged on Brussels for the demonstration.

Primary education bore the brunt, with schools forced to either cancel classes or switch to remote learning, with some facilities completely shut due to shortages. Secondary schools were less affected, largely maintaining regular classes or implementing online alternatives.

The strike severely disrupted public transport nationwide, limiting train services to just one-third of normal operations between major cities. The capital's metro, tram, and bus services were reduced, while in Wallonia, the French-speaking region, most bus routes ceased entirely.

Unions condemned the pension proposals as an "attack on pensions", demanding better working conditions, higher employer contributions, and reduced career lengths for physically demanding jobs. They also opposed corporate tax concessions, claiming the reforms would unfairly burden workers.

ABVV-FGTB socialist trade union federation leader Thierry Bodson warned about escalating actions once a government deal emerges.

"We'll be stepping up a gear, and that may even mean a general strike if we want to be heard," he said. Union organizers have already scheduled their next demonstration for Feb 13 in Brussels, when they intend to shift their focus to defending public services.