A ‘lockdown’ approach to bar pupils from leaving school in search of unhealthy lunches is unworkable, say Bradford education chiefs.

Rob Rees, chairman of the School Food Trust, an independent charity set up to improve the quality of food consumed in schools, wants pupils to be banned from leaving school premises at lunchtimes to stop them buying fast food.

He said: “Schools are working really hard to give teenagers a lunchtime experience that can rival the high street whilst still being healthy.”

But Bradford East MP David Ward, acting education spokesman for Bradford Council’s Liberal Demo-crat group, said pupils should be trusted to make their own decisions.

“I can see why there are calls for a ban, particularly given problems with obesity in Bradford but it is going too far by extending it to a ban,” he said.

Pam Milner, Bradford branch secretary for NASUWT, rubbished the idea of a lockdown.

She said: “The lock and bolt approach would cause students to go stir crazy and that’s not good for positive behaviour. It’s another example of the nanny state. Who’s going to police it? It’s totally unworkable.”

New research commissioned by the campaign group, Consensus Action on Salt and Health, found takeaway meals sold near schools could contain more than one and a half times more salt and three times more saturated fat than an adult’s maximum recommendations for a day.

Pupils aged under 16 who attend St Bede’s Catholic Grammar School, in Heaton, are not allowed to leave school at lunchtimes – barring access to a bakery, convenience store and fish and chip shop opposite the school in Highgate.

A spokesman for the head teacher Paul Martin said this was purely for “safety reasons”.

Sandra Robertshaw, who runs The Village Bakery, said: “We get children in first thing in the morning and after school. The sixth-formers come at lunchtime.

“Some children, though not so much now, come in and ask for a loaf of bread to be scooped out and they go to the fish and chip shop to get them filled with chips.

“The boys eat the sugary stuff. The girls will ask for a slice of lettuce in their bacon sandwich and sometimes get an iced bun to go with it.”

Harish Patel, who runs Highgate News next door, said: “It’s down to the children themselves to choose.”

Last year, data recorded for eight Bradford secondary schools showed 35 per cent of pupils opted for school meals.

e-mail: ben.barnett@telegraphandargus.co.uk