PARIS: More than a million French workers marched Tuesday in the biggest protest yet against President Nicolas Sarkozy's pensions reform, threatening to extend strikes disrupting trains, planes and refineries. Students and school pupils joined the movement for the first time and staff in several sectors threatened to make the strikes open-ended, escalating the toughest battle of Sarkozy's presidency, as the government dug in its heels. Turnout estimates logged it as the biggest street protest in strike-prone France since 1995, when a month of stoppages crippled the country and forced the right-wing government at the time to drop its own pensions reform. As a huge march snaked its way though the streets of Paris near the national assembly, Prime Minister Francois Fillon defended the pension plans during a rowdy parliamentary session. “We are determined to carry through this reform,” he stated, and slammed as “irresponsible” what he said was a bid by the far left and some opposition Socialists to “put kids of 15 on the streets” to join the protests. Opposition Socialist leader Martine Aubry accused him of overseeing a measure that “symbolizes all the injustices and inequalities that characterize his policies and which the French find intolerable.” Operations at 11 of France's 12 mainland oil refineries were disrupted and 56 tankers were stuck waiting off the Mediterranean port of Marseille as petrol and dock workers held an open-ended strike. Travellers faced major delays, with up to half the flights to and from Paris Orly airport and one in three at the capital's international hub Charles de Gaulle-Roissy and the smaller Paris Beauvais cancelled. Around 30 percent of flights were canceled at France's busiest airport, Paris' Charles de Gaulle, while cancellations at the capital's second airport, Orly, reached 50 percent, according to aviation authorities. Most of the affected flights were short-haul domestic flights or inter-European flights, said Eric Heraud, spokesman for France's DGAC civil aviation authority. Even getting to the airport was a challenge Tuesday. As 1 P.M. (1100 GMT), no trains were running on the suburban RER B-line that links central Paris to both airports, according to Paris' RATP public transport authority. Workers at all six of oil giant Total SA's French refineries were striking, and two of them had begun preparations for total shutdowns, said company spokesman Michael Crochet-Vourey. Just one in three TGV high-speed trains was running, although Eurostar trains between Paris and London operated normally. Paris commuter and metro trains were also hit as transport workers walked off the job. Strike action also forced the closure of Eiffel Tower, one of the world's most popular tourist sites. Students at around 400 high schools across the country built barricades with plastic wheelie bins or used other methods to try to prevent other pupils attending classes, the education ministry said. “I'm prepared to prolong the strike. I started working at 17 and now I'm 50 and I'm starting to get really fed up with it,” said a demonstrator in the southwestern town of Angouleme, who said he worked for the Lafarge cement firm. A CSA opinion poll said 69 percent of French people back the strike, with 61 percent in favor of more open-ended industrial action. “I do not think we have lost the battle of opinion,” the architect of the reform, Labor Minister Eric Woerth, said on television on Tuesday evening.