More than 100,000 pensioners face losing benefits of up to £2,000

More than 100,000 pensioners could miss out on benefits of up to £2,000 under changes due to come into force later this year.

From October 6, those applying for pension, housing or council tax benefit will have their claims backdated for only three months, rather than the current year limit.

Figures compiled by the Department for Work and Pensions show 110,000 pensioners claim arrears for more than three months -with 70,000 making backdated claims for the whole year.

The average backdated claim in 2006-07 was for £700, but some received up to £2,000.

Under the new rules, meant to make it easier to apply for means-tested benefits, people will be able to claim the pension credit, council tax benefit and housing benefit with a single phone call without having to fill in a form.

But the reform will be funded using the £100 million that the Government estimates it will save by limiting the backdating of payments. Money saved will also going towards increasing the pension credit and winter fuel payment.

Around £5billion in handouts go unclaimed each year.

John Barrett, Liberal Democrat work and pensions spokesman, said that there was 'no justification' for making the changes.

'The simple reality is the most vulnerable pensioners will miss out on hundreds, perhaps thousands of pounds as a result,' he added.

Vicky Pearlman, of Citizens Advice, said: 'It will have a huge detrimental effect, especially in the current climate of soaring energy and food prices.'