A small wildcat strike of workers at a rail station in southern Belgium last week has spread to all public sectors of the country and turned into the first massive protest of the country's two-year-old austerity program.

Rail, bus, subway and tramway workers joined in the strike Tuesday and their actions have brought the country to a complete halt. More of the nation's 900,000 state employes joined the movement Wednesday, including teachers, firefighters, rubbish removers, air controllers and civil servants in the capital and provinces.

The actions paralyzed the port of Antwerp and union officials said Thursday that Belgium's other main port at Zeebrugge could close. They also threatened no trains would circulate through the country.

This is the first time since the center-right coalition of Prime Minister Wilfried Martens came to power two years ago that unions whose parties belong to the government have called for an all-out general strike to protest proposed cuts in public spending. Because of this, Liberal and Social Christian trade unionists are finding themselves in an unusual alliance with their Socialist counterparts in the opposition.

The strike is limited to the public sector, but union officials say workers in private industry, particularly at steel plants in Wallonia where 8,000 lay-offs are expected this year, are likely to stay off the jobs in a show of solidarity.

The protests began spontaneously Friday at the railway station of Charleroi in Wallonia, and they caught all unions by surprise.

"We're trying to show the government that we're fed up," said Robert Manchon, a teacher. Specifically, state employes are reacting against Martens's latest attempts to curtail a budget deficit that absorbs about 16 percent of the gross national product.

The government announced this summer $175 million worth of reductions in wages and welfare benefits for state workers. The belt-tightening includes a halt to automatic salary increases of 3 percent every two years, a partial suspension of the indexation system for pensioners who receive relatively high allowances per month, a 12 percent cut in vacation allowances and a 20 percent reduction in work and pay for starting government employes.

Some strikers, including Manchon, said their aim is to force the fall of the Martens government, which so far has shown remarkable endurance in a country whose revolving-door governments rival Italy's. But government officials say they are confident this coalition will weather the storm.

Emerging from a meeting with the unions earlier this week, Deputy Prime Minister Jean Gol, who is standing in for Martens while he recuperates from a heart operation, said the government was determined to carve $175 million out of the budget deficit but was ready to negotiate how this could be achieved.

(Gol told reporters Friday that the government would make fresh proposals to trade union leaders Saturday in an attempt to end the strike, Reuter reported.)

(He said a first round of talks between the two sides had dealt with complaints about public service employment, as well as with the government's budget problems.)

(Political sources said the government was considering some inducements for ending the strike. They said possible measures included promises not to cut state employes' seniority and productivity bonuses, seen by the unions as under threat in the government's austerity drive.)

(Gol also told reporters earlier that in a Cabinet meeting that morning the government had reaffirmed its intentions to keep the country's budget deficit down to no more than $10 billion next year, the news agency reported. Asked about the speculation that the government coalition could fall, he said, "That's about as far away as the moon."