City centre streets will be closed to traffic in the run up to Christmas in an effort to cut congestion and improve road safety for shoppers.

Police will close busy Chapel Street and Butler Street at their junctions with Fishergate, on Saturdays and Sundays, from about 10am-4pm, and at similar times every day during the week before December 25.

Under Operation Decongestion, which starts on Saturday, motorists will be allowed to use the bus lane in Fishergate from Chapel Street and traffic regulations prohibiting drivers from stopping in yellow box junctions will be rigorously enforced.

PC Dave Taylor, of Preston police's traffic management team, said the closure of Chapel Street was to protect pedestrians at its busy Fishergate junction which often becomes bottlenecked with vehicles, bringing the whole centre to a gridlock.

"Thousands of people pass through the junction, and sometimes it is eight or ten people deep and they just spill out on to the road. People cross even when the red man is showing," he added.

John Asquith, traffic manager of Preston Bus, hailed the plan as "fantastic news" saying the two junctions were key to congestion in the city.

"When Butler Street gets blocked it snarls up Corporation Street, Ringway, and Lune Street, and equally with Chapel Street it snarls up the car park exit for the Mall St Georges and Lune Street."

PC Taylor said shoppers wanting to park at the Fishergate Shopping Centre should access the car park via the underpass off Corporation Street.

And drivers needing to access the railway station via Butler Street should ask the police officer staffing the junction to open the temporary barrier, he added.

He warned motorists not to try to bypass the closures by using Mount Street or Winckley Street.

"Our advice is for drivers to use Ringway, there will be considerable delays at Mount Street," he added.

Signs have appeared on major arteries into the city warning motorists of the closures of Chapel Street, and police hope the operation will help businesses profit from increased trade as a result of less congestion.

PC Taylor added: "It's fair to say that the highway network in the city centre is somewhat antiquated and in need of a review, but this operation is aimed at improving pedestrian safety and reducing congestion."

He said the operation would run until Christmas Eve and there were no plans to make the arrangements permanent.

Julia Horn, general manager of Preston and District Chamber of Trade, said the plan reignited the debate about the pedestrianisation of Fishergate, something the chamber has long campaigned for.

"I think that we have got to try things like this, if it makes for a happier shopping experience then I think it's a good thing," she added.

Keith Mitchell, manager of the Fishergate Shopping Centre, said he was supportive of road closures during this period.

He added: "If drivers can pass through the city quicker when they come in they will visit more often."

A spokesman for Lancashire County Council, which has responsibility for the road network, said signs were located around the city telling drivers how many spaces are available on car parks.

And Chapel Street has already been earmarked for a study into junction improvements, under the Civitas Success scheme.