A film souvenir Batman knife landed an Atherton man behind bars for four months.

Todd Rushworth, who had never been in trouble before, was told by a judge that knife crime was so serious a deterrent sentence had to be imposed.

"The message needs to go out loud and clear to anyone who carries a knife that there is zero tolerance as far as this court is concerned," said Judge Nigel Gilmour QC.

"This knife is extraordinarily sharp and very pointed. Both blades can be taken out and locked in position so someone holding it in their fist could have this potentially lethal knife opened out in both directions," he said.

Liverpool Crown Court heard that 19-year-old Rushworth had the knife with him for protection following threats after he went out with another man's ex-partner.

Judge Gilmour said if there had been a confrontation he would have been tempted to reach for it "and who knows what might have happened. That knife could have caused serious injury with little force at all".

He added: "Young men who are tempted to go out with knives must know, even if they are of good character, if they are caught they will go to prison."

Rushworth, of Sumner Street, Atherton, pleaded guilty to possessing the knife in a public place on October 16.

David Owen, prosecuting, said that Rushworth was stopped by police in Bag Lane, Atherton, and when searched the weapon, which had three-inch blades, was found in his pocket. When questioned he said he was carrying it for his own protection.

Ben Jones, defending, said that Rushworth is an immature young man who had no intention of using the "fearsome" knife, which had a Batman logo. He had it with him in a moment of foolishness.

He had the knife for more than a year having bought it as a souvenir of the Batman film.

"It had been glamourised by the film," said Mr Jones.