THE French prime minister has told the unions behind a crippling railway strike that he is open to backing down on controversial proposals to raise the full pension age to 64.

Prime Minister Edouard Philippe, a member of the Charles de Gaulle-inspired Les Republicains party, wrote to unions one day after the French government and labour representatives engaged in talks that had seemed to end in stalemate.

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After more than a month of strikes and protests, Philippe’s letter said the plan to raise the age of eligibility from 62 to 64 – the unions’ major sticking point in wide-ranging pension reforms – is open to negotiation.

It was the first time the French government overtly indicated room for movement on the issue. The overture could signal hope for ending France’s longest transport strikes in decades, now in their 40th day.

However, the General Confederation of Labour (CGT), one of France’s biggest unions, called the proposal “a smokescreen” and said it was “more determined than ever” to stop all of the reforms, rather than accept a single concession.

On Saturday, protesters in Paris marched through the streets to denounce the French government’s overall pension changes. Demonstrators set fire to a kiosk near Bastille square in the centre of the city as a minority of participants in the march turned violent. Police fired tear gas as struggles broke out.

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Two days earlier, hundreds of thousands of protesters took to the streets nationwide to denounce the government’s pension proposals.

The unions have planned further action for next week to keep up pressure on the government.