This article is more than 9 years old

This article is more than 9 years old

Retiring at 62 became law in France today in a victory for Nicolas Sarkozy's conservative government and a defeat for unions after strikes and street protests were held in an attempt to halt the austerity measure.

The law was published in the government's official journal today – meaning Sarkozy has signed it and it has gone into effect.

The constitutional watchdog approved the plan yesterday after the French parliament passed it on 27 October.

Sarkozy's success gives him an international boost as France prepares to take over the leadership of the G20 group of leading economies from Friday.

Protests at having to work an extras two years by trade unionists and students had disrupted train and air travel, caused petrol shortages and allowed rubbish to pile up in the southern city of Marseille.

More than a million people had repeatedly taken to the streets, but Sarkozy said today that the French pension system had been "saved".

"[I am] fully aware that this is a difficult reform," he said. "But I always considered that my duty, and the duty of the government, was to carry it out."

Unions argued that retirement at 60 was a cornerstone of France's social security system, but the government said the pension system would have been jeopardised without the change because French people are living longer – an average of nearly 85 years for women and 78 for men.

The reform means the minimum retirement age is now 62 instead of 60. Those who want to claim full pension benefits must now wait until age 67 instead of 65.

France's opposition said Sarkozy had not taken complaints about the reform seriously. Speaking on France Culture radio, the Socialist leader, Martine Aubry, said Sarkozy "thinks that by keeping his head down and not listening to anybody, he's showing courage".

Sarkozy's approval ratings are hovering around 35%, near their lowest levels since he took office in 2007. He has yet to announce if he will run in the 2012 presidential election but, with the pension reform behind him, can now try to rebuild his popularity at home by turning to less controversial matters.