Women hit hardest by move to equalise retirement age at 66

Women in particular will be hit hard by the announcement, which will equalise the retirement age at 66 by 2020. Labour had planned to increase the male state pension age by 2024, so that timetable is being accelerated by four years. It had also planned for the female age to go up only to 65 by 2020.

The changes, which until today have only been mooted by ministers, will save the Government £5 billion a year in 2015. It estimates it will save a huge £30 billion between 2015 and 2025.

The state pension age for women will start to gradually increase from 2016, by three months in every four rather than the current plan of going up by one month every two. The age for men and women will be gradually equalised from 2018 to 2020. The Government hopes to offset the impact of the changes by restoring the link between pensions and earnings by 2012. It is also changing the law so that workers will no longer be forced to retire by 65.

Although the time frame of the proposals falls outside today's Comprehensive Spending Review, Chancellor George Osborne is determined to drive through the changes as part of his long-term goal of cutting state spending.

Unions have warned that the plans could hit those in manual labour jobs particularly hard. Unlike most office posts, blue-collar jobs may not be physically possible beyond 65, they claim.

But to date, opinion polls in the UK have shown that the public are relatively sanguine about the principle of raising the pensionable age limit.

By contrast, France has been dogged by strikes over proposals to raise its retirement age from 60 to 62 and the state pension age from 65 to 67. But with soaring longevity, all Western countries are having to come up with ways to afford the cost of their elderly populations.

The last Labour government's 2007 Pensions Act planned for the pension age to rise to 66 by 2024 and 68 by 2046. The changes were due to affect everyone born after April 6, 1959.

The state pension age for men has been 65 since the Second World War. However, at the time the average life expectancy for a man was 66.4 years and 72.5 years for women.

By last year, life expectancy was 77 for a man and 82 for a woman. Latest figures suggest longevity will rise further so that by 2056, a man can expect to live to 84 and a woman to 89.

Mr Osborne first floated the idea of hiking the pension age at last year's Tory party conference, although he stressed at the time that "no one who's approaching retirement soon... will be affected".