The government is in danger of missing its pension credit targets, a charity has claimed, after figures revealed that fewer new people were claiming it.
The government launched the extra help for pensioners in October 2003
The Office for National Statistics (ONS) said 265,00 new claims were made in the year to May, down from 296,000 during the previous 12 month period.
Age Concern said the government may now struggle to meet its aim of reaching 3.2 million households by 2008.
Pension credit is currently paid to about 2.73 million people.
However, almost a third of the people who are eligible for the benefit do not claim their cash, leaving about £2.5bn unused.
Pension credit was introduced in October 2003, and has two parts.
The guarantee credit tops up the income of eligible claimants aged 60 and over to a set amount, whilst the savings credit can provide extra money for people aged 65 and over who have extra income.
Pension credit has always been controversial. Critics argue the system is too complicated, and say many older people find means-testing intrusive and demeaning.
The latest ONS quarterly report revealed that the number of new pension credit claims fell by 31,000.
According to the report, pensioners receiving the benefit were paid an average of £50.04 a week in May, £3.29 more than a year earlier.
Take-up of pension credit has remained consistently around the two-thirds level since the benefit was launched.
Age Concern says its research shows 6 out of 10 lower income pensioners are put off claiming by the complexity of the system.
"We are calling on the government to make it easier for older people to claim benefits by introducing a single claim-line for all means-tested benefits or paying benefits automatically to all those entitled," said the charity's director general Gordon Lishman.
A spokesman for the Department for Work and Pensions defended the government's record.
"Since pension credit was introduced more than 700,000 pensioners have been lifted out of poverty. Pension Credit means that no pensioner needs to live on less than £119 per week."
"We are absolutely committed to getting extra help to pensioners, and will continue to work with organisations including Age Concern and Help the Aged," he added.