Government efforts to ­persuade the public to eat more fruit and vegetables appear to be having only a marginal impact on the national diet.

The five-a-day scheme, aimed at encouraging everyone to have at least five daily portions of fruit and vegetables, was launched in March 2003.

But average consumption of fruit and vegetables is still estimated to be only slightly more than half the recommended amount.

Caroline Flint, minister of state for public health, has admitted to the Commons that Whitehall figures show that "overall, households have not seen a huge change in the purchasing of fruit and vegetables". Latest estimates indicate that only just over a third of the population is consuming the level of fruit and vegetables recommended more than a decade ago by the World Health Organisation,

The WHO recommended that people should eat 400g of fruit and vegetables daily. Since the scheme began, the DH has spent about £2m a year promoting it. This funding is apart from a separate programme for promoting fruit and vegetables in schools.

Food Standards Agency surveys, however, have found an increase in awareness of the five-a-day message, going from well under half the population to more than two thirds last year.

But class and regional factors are influential. Average consumption of fruit and vegetables by women in the highest income brackets are shown to be almost twice the levels of men in the lowest income quintile.

Flint defended the programme, telling MPs that there had been "a significant increase" in the amount of fruit and vegetables purchased by the poorest families.

Studies have repeatedly shown that eating substantial quantities of fruit and vegetables may reduce the risk of heart disease and some cancers - illnesses causing 60% of all early deaths in the UK