Civil servants, from teachers to air traffic controllers, began a mass walkout Tuesday, the seventh day of a transport strike that has wreaked havoc on French rails. But the government said it would not cede on planned reforms.

Despite the increased pressure on President Nicolas Sarkozy, the government stood firm, with Prime Minister Francois Fillon saying the reforms must go through — even though the rail strikes are costing the country at least $439.6 million a day.

Budget Minister Eric Woerth told France Inter radio on Tuesday that the strike by public transport workers could have an impact on France's economic growth if it lasts.

Strikes led by train drivers angry over Sarkozy's plans to raise their retirement age have hampered rail traffic and public transport in Paris for a week.

On Tuesday, schools, postal and tax services fell victim to a strike by civil servants seeking higher salaries and job security as the government works to whittle down the bureaucracy. Air traffic, too, was expected to be affected.

Simmering student protests that have disrupted classes at dozens of universities added yet another dimension to the angry fallout from Sarkozy's efforts to jolt France into a more competitive era.

But authorities continued to refuse to meet union demands.

Government spokesman Laurent Wauquiez said Tuesday that a state representative will not be at the negotiating table Wednesday with rail workers — as unions have stipulated — unless more strikers return to work.

"We have always been very clear about this," he said on RTL radio. "If we want talks with everyone at the table, each must do his part."

In fact, authorities have backed off slightly from the original government position of no talks during strikes. But Fillon, the prime minister, said Monday that rail traffic must "progressively restart" before the talks can begin.

There were no immediate signs that the various movements planned to fuse their efforts — simultaneous but separate — into a single blanket protest.

Rail workers were not expected to join an afternoon protest march in Paris by striking civil servants — although students may.

The conservative president, who has often jumped into disputes to sort them out himself, has remained curiously silent about the strike.

Sarkozy was elected in May on promises to reform France — from its courts to its creaking university system, its army of civil servants to rail workers whose special retirement privileges he vowed to erase.

Taking on the transport workers has proved to be especially thorny — and costly.

The strikes are costing the French economy between $439.6 million and $512.7 million a day, Finance Minister Christine Lagarde said Monday.

Civil servants seeking pay hikes moved to center stage Tuesday. Up to half of teachers could stay off the job, officials have said. Air traffic controllers fall into the civil servants' category, disruptions are expected. Air France, whose personnel were taking part in the job action, said flights, mainly domestic, would be modified from Marseilles and Paris' Orly airports.

National newspapers couldn't be found Tuesday as printers and delivery personnel join the strike. Though not state workers, they are using the opportunity to protest job cuts.

Students also were joining Tuesday's protest. Knots of students have been blocking universities around France for two weeks to protest a law passed this summer allowing universities more autonomy to seek nongovernment income. They fear the changes mean schools will close their doors to the poor.

In a clear bid to appease, the minister in charge of civil servants' affairs, Woerth, said he hoped to conclude a new salary agreement soon — the first in 10 years.

But the head of the FSU union, speaking for civil servants, warned the government not to dismiss their complaints.

"They seem to believe this is just a movement of anger that will pass," Gerard Aschieri said, adding that "this is to underestimate the discontent."