By Brian Love
PARIS (Reuters) - French trade unions said 2.5 million people took to the streets on Tuesday to protest over pension reforms that President Nicolas Sarkozy says he is determined to implement on the way to elections in 2012.
Tapping into mounting unease over austerity as Europe emerges deeply indebted from recession, French union leaders demanded the centre-right government heed their call to backtrack or run the risk of an escalation.
"If they don't respond and they don't pay heed, there'll be a follow-up and nothing is ruled out at this stage," Bernard Thibault, leader of the large CGT union, told a Paris rally.
Millions of commuters across the British capital also struggled to get to work as a 24-hour strike by workers on London's underground rail system crippled much of the network, hurting the city's convalescent economy.
The French strikes cut national rail services by 50 percent or so and disrupted underground train services in Paris but not as much as first feared. One in four flights at Paris airports was cancelled.
Some 2.5 million people protested in all, according to a CFDT union spokesman, topping the two million the unions say participated in June for a previous protest. The official estimate from the interior ministry, which is always far lower than organisers' tallies, was 1.1 million.
In the riviera coast city of Nice, one of myriad protests nationwide, protesters brandished banners to say: "Our pensions are ours. We fought to earn them, we will fight to keep them."
Analysts said the large protest turnout would probably not be enough to secure much more than marginal concessions beyond the essentials of what many regard as the flagship of Sarkozy's five-year term, which ends in early 2012.
Those essentials are a rise to 62 from 60 in legal minimum retirement age, and a rise to 67 from 65 in the age at which people are entitled to retire on a full pension, al part of a plan to balance the finances of the system by 2020.
"For the unions, today is a victory in terms of turnout," said Jean-Francois Doridot of the opinion pollsters IPSOS.
"But the point is to make progress on the draft law, to make changes to the text, which they will have difficulty doing. So we can talk about a victory that is symbolic, rather than real."
As protesters marched, Labour Minister Eric Woerth, battered by a scandal over alleged conflicts of interest and illegal political donations, defended the pension reform bill in parliament, which is due to adopt the bill next month.
A question session in the National Assembly, the lower house of parliament, was briefly halted as Communist deputies staged a boisterous protest in front of the beleaguered minister.
Opinion polls show two-thirds of voters think Sarkozy's plan is unfair, but the same number thinks the strikes will make no difference.
"Never in polling history have the French people been so convinced that there's a social injustice," political analyst Roland Cayrol, from Paris's Sciences Po institute, said.
With Sarkozy's approval ratings close to all-time lows, the government is under pressure to cede some ground, and Woerth repeated that the reform could make allowances for people in jobs where the wear and tear is extreme over time.
France's strikes mostly were in the public sector but some 700 steel workers downed tools at an Arcelor Mittal plant in northeastern France to highlight that side of the problem.
"We work 365 days a year in extreme conditions. Dust and noise means we are wearing ourselves out and going beyond 60 years old will send us to a certain death," Edouard Martin, a CFDT union representative, told I-tele TV.
Senior Sarkozy advisers hinted on Sunday he could make further concessions beyond the pension bill itself, such as amending a widely criticised "tax shield" put in place to ensure the wealthy do not pay more than 50 percent of their income to the state.
The labour unrest mirrors action in other European countries against austerity measures as governments strive to reduce the debts run up in the recession of 2008-09.
Governments in Greece, Spain, Italy and Romania have so far faced down strikes to impose painful pay and spending cuts.
Many European countries have an official retirement age of 65, and some, such as Germany and Britain, plan to raise it gradually to 67 or beyond. But the real effective retirement age in France is similar to that of its neighbours, according to the Organisation for Economic Cooperation and Development.
France has a tradition of labour militancy although only about 10 percent of workers are unionised, mostly in the public sector. A 1995 revolt forced former President Jacques Chirac to abandon planned pension and healthcare reforms, and 2006 student protests killed plans for a low-wage youth employment contract.
But the mood is different now, with many people accepting that longer life expectancy and weaker public finances make a raising of the retirement age inevitable.
"Unlike 1995, when similar numbers took to the streets, there isn't the feeling (this time) that they can win something out of it," said Sciences Po analyst Cayrol.
(Additional reporting by Elizabeth Pineau, John Irish, Vicky Buffery, Nick Vinocur, Thierry Leveque and Gerard Bon, editing by Michael Roddy)
