The government is to commission more research into the link between retirement age and life expectancy as it tries to break the deadlock in the long-running talks to reform the pension system.

The current system, in which the age when workers are entitled to receive their pension will rise in step with life expectancy after 2021, was a bone of contention between unions and employers.

The FNV union has called for the increase to be scaled back so that the age increased by six months for every extra year that workers were predicted to live. The cabinet said the move would cost the public purse €6 billion in the long term.

The government says it has already made concessions to the unions by freezing the retirement age at 67 for the three years until 2024. But the negotiations, which began seven years ago, broke up last week without agreement.

A majority of MPs backed a proposal by Christian Democrat (CDA) leader Sybrand Buma to study the projected increase in life expectancy and its consequences in more detail.

Prime minister Mark Rutte said any major extra investment in the pension system would have to wait until after the next election,’ he told parliament. ‘These sort of big questions need to be dealt with when you’re negotiating a coalition agreement. Don’t ask a sitting cabinet to find another €6 billion from its budget. That’s not democratic.’