France's leftist France Unbowed (LFI) party will take new legislative steps on Tuesday to scrap President Emmanuel Macron's contested pension changes and reverse the rise of the legal retirement age to 64 from 62, its chief lawmaker said.

Cancelling the reform - which is aimed at protecting the state's finances and boosting productivity - is one of the main projects of France's left-wing camp which emerged as the strongest force from snap parliamentary elections last month while falling short of a majority.

"We will, today, put down a legal proposition to cancel the pension reforms," said Mathilde Panot, who heads France Unbowed in the lower house of parliament, on France Inter radio.

The reform resulted in violent street protests last year, due to widespread opposition from workers.

LFI's bill, which is unlikely to voted on before September, would need the support of lawmakers beyond the New Popular Front left-wing coalition to pass.

The right-wing National Rally party had also campaigned on lowering the retirement age while Macron's centrist bloc and other centre-right politicians said they would oppose such a move.

France is in a state of parliamentary deadlock since Macron's decision to call the election, with the current government likely to carry out its functions throughout the summer in a caretaker capacity.