Ministers have warned the food industry to "get serious" about reducing the salt content in popular products.

The Times revealed on Thursday that health minister Melanie Johnson had written to major companies warning them that the salt content in some processed foods was still too high.

Government Response: Department of Health

Melanie Johnson public health minister said:."What is needed are real commitments for key product categories such as pizza, breakfast cereals, sandwiches and ready-made meals to ensure that we reach the necessary reduction in salt intakes from processed foods."

Party Response: Liberal Democrat

Paul Burstow, Lib Dem health spokesman, said: "This weak plea to food companies shows that the government's approach on public health is pathetically inadequate.

"A clear traffic light system for food labelling is needed, which would help busy shoppers find out the fat, sugar and salt content of the products in their trolleys."

Forum Response: World Cancer Research Fund

Andrew Trehearne, head of education and communications at WCRF UK: " The World Cancer Research Fund (WCRF UK) supports the Department of Health's determination to get food manufacturers to cut down excess salt in processed foods.

"This will help to prevent diet-related illnesses such as hypertension and cancer. In its 1997 expert report, WCRF UK concluded that 'diets high in salted foods probably increase the risk of stomach cancer'.

"WCRF UK recommends that the intake of salt for an adult should be less than six grams per day (0.25 ounces). Children should consume less than  three g/1,000 kcal and babies should have no salt at all added to their food.

"Unfortunately, most of us in the UK consume a great deal more salt than this. In fact, the International Conference on Salt and Health in 2002 stated that salt consumption in the UK runs around nine to 15g per day, about 80 per cent of which comes from processed foods.

"As consumers, we currently have no control over the 'hidden' salt in processed foods unless we carefully scrutinise the food labels on every packet that we buy. And all too often we can't understand these labels anyway!

"What is required is a clear, accurate and simple guide to what is in the food we eat. We should be able to immediately see if we are eating a product that is high/medium or low in salt.

"WCRF UK hopes that food manufacturers will respond to the government and further reduce the levels of salt in processed foods swiftly. On such an important issue, we can't afford to wait!"

Forum Response: British Retail Consortium

Dr Kevin Hawkins, director general of the BRC, said: "The BRC is disappointed that the minister released the letter to the press in advance of actually sending it to us and the other recipients.

"She did not even send a response to our proposals on salt, but issued a generic letter that totally failed to recognise the progress retailers have made over this issue.

"It is obvious from her comments that the minister has seriously underestimated the work done by the retail sector over the last five years to reduce salt and has not taken on board the commitment that the BRC made to the Department of Health in February to reduce salt in nine product categories to achieve the six gram target."