The state pension age is set to rise seven years earlier than expected, forcing millions of Britons to work for years longer.

The retirement age is set to gradually rise to 68 between April 2044 and April 2046, affecting those born between April 1977 and April 1978.

But Treasury officials have now told the Office for Budget Responsibility (OBR), the Government’s fiscal forecaster that the “current policy” is to bring the rise forward by at least seven years.

Around five million people now aged between 49 and 55 would be made to work an additional year before being eligible for their state pension, costing them about £12,500.

Ministers launched a review of the state pension age last year.

Led by the Government Actuary’s Department and Suzy Morrissey, the deputy director of the Pension Policy Institute, the review will make recommendations on when the pension age should rise – before any change is made by Labour.

The decision would save the Treasury an estimated £6billion a year from 2037 compared to the current timetable.

In a response to the OBR, the Treasury said it intended to bring forward the pension age towards the end of the next decade.

The OBR said: “We assume that the state pension rises to 68 in 2037-39. The Treasury has confirmed to us that this is the government’s current policy position, rather than the legislated increase set in the Pensions Act 2007.”

This would cost the Treasury an “average additional £6billion in today’s terms in each of the years the state pension age rise is delayed,” the OBR said.

The Treasury said the plan to bring forward the rise dates back to 2017, when Theresa May’s Government accepted the findings of a review by John Cridland, a former director of the Confederation of British Industry.

Read More: State pension age to rise seven years earlier than expected in blow to millions of Britons