"Many women are angry that the system fails to give them a decent income and it is an issue that is likely to affect their votes on polling day."

Plans to bring the pension age for women to 65 from 2010 would lead to an "expectation of equality with men", said the report, but would not improve the situation for modern women.

"Women tend to receive lower pensions because they earn less than men during their lifetimes. Increasing the pension age will not change this and will do nothing to reduce the number of pensioner women living in poverty," said Dr Katherine Rake, director of Fawcett.

The charities recognised that the government had gone some way to easing poverty amongst women pensioners with the introduction of pension credit, which has lifted 1.8m pensioners out of poverty (three-quarters of whom are women).

But the pension credit system further complicates an already complex system, and many people fail to claim benefits simply because they are unaware they are entitled to extra money.

The latest government figures show that for 2002/3, 550,000 single women pensioners were living below the poverty line because they didn't claim all the benefits to which they were entitled.

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