Food additives and colourings have turned Sussex youngsters into time bombs capable of violence, says an MP.

Wealden's Charles Hendry, shadow minister for young people, said one of his constituents suffering from hyperactivity had tied his younger sister to a fence with a rope around her neck.

He added: "In another case, a young boy went on the rampage with a kitchen knife. The families of such children live in constant fear, not knowing how they are going to react at any particular moment."

Mr Hendry called for clearer labelling of all food containing additives and colourings, which may have an adverse effect on youngsters, during a ten-minute rule bill at Westminster yesterday.

He said simply making parents aware of the dangers could have a huge impact.

According to the Food Commission, 40 per cent of children's food and drink contains additives.

The commission has found more than 100 food products targeted at children which contain the main additives it has identified as likely to cause behavioural change.

Mr Hendry said: "The evidence is clear. Part of the cause of hyperactivity is the presence of certain additives and colourings in food specifically targeted at children.

"It is not the only cause, it may not even be the main cause; but it is a contributory factor."

To emphasise his point, Mr Hendry waved a packet of raspberry-flavoured trifle in the chamber of the Commons.

He said apart from a small amount of powdered egg, the product contained "no food whatever". Instead it was made up of additives, colouring and stabilisers.

Mr Hendry said links between these ingredients and behaviour problems had been established by Hyperactive Children's Support Group in Chichester.

Links have also been studied by Professor Erik Millstone at the university of Sussex, who analysed US research showing up to 50 per cent of hyperactive children experienced a dramatic improvement in their behaviour if they avoided certain food additives.

Mr Hendry said his Bill would force food producers to put a simple label on items for sale.

It would read "This product contains colourings or additives which may affect the behaviour of some children."

The Bill has cross-party support, including the backing of East Worthing and Shoreham MP Tim Loughton, but is unlikely to become law. Instead, Mr Hendry is hoping health ministers will act upon his ideas.