A PAIR of teenagers who launched a bungling attempt to rob a Chippenham petrol station in the dead of night have been jailed.

Euan Skinner, 19, and a 16-year-old, who cannot be named, were high on drink and drugs when they persuaded a cashier to open the door of the service station to them.

But when the masked raiders threatened him with knives the man fled into a back room and locked himself in for half an hour, while the pair left empty-handed.

Colin Meeke, prosecuting, told Swindon Crown Court how the incident took place at about 2.30am on October 13 last year.

He said CCTV footage from the Esso on Bath Road, Chippenham, showed the youngsters going to the cash machine outside the garage.

The pair then went to the night window and convinced the man who was working in the shop to let them in.

Once inside they went to the counter and one produced a knife with an eight-10 inch blade and the other a smaller kitchen knife.

Mr Meeke said the cashier at first thought they were joking, but soon realised they were not so fled into the office and locked the door.

"He was so concerned he stayed there for 30 minutes to ensure that all was safe," he said.

The CCTV footage showed the pair, neither of whom have previous convictions, turning round and walking out of the store at the bottom of Rowden Hill.

Mr Meeke said the pair were caught after police found out that the younger lad's card had been used in the cash machine shortly before the raid.

When he was questioned he told who the other man was and how they had come up with the idea of getting more cash after drinking heavily.

"Each said it was the other's idea, each blamed the other for the knives," Mr Meeke said.

"They said they aimed to get some money then some alcohol and put the plan into execution. They appeared to realise the enormity of what they had done."

Skinner, of Leftwich Manor Guest House, Cheney Manor Road, Swindon, and the 16-year-old, of Chippenham, admitted attempted robbery and having a bladed article.

Tony Bignall, for Skinner, said that for a period of a few months around the time of the offence his client had gone off the rails.

"It was a robbery by virtue of its plan but it was bungled. They persuaded the man to let them in because he knew them," he said.

"They quickly abandoned it when the cashier hid himself, they didn't try to persuaded him to come out."

He said at the time he had been using MDMA, the chemical form of ecstasy, and alcohol.

Michael Butt, for the younger teen, said that his client had been doing a lot of work with the Princes Trust and had been diagnosed as having ADHD and Tourette's Syndrome meaning he got Disability Living Allowance, which is why he was the one at the cash machine.

Jailing them, Judge Tim Mousley QC said "These offences are just too serious for me to impose any sentence other than an immediate custodial sentence.

"There was obviously some planning, albeit done by you two in a haze of drugs and alcohol. That can be the only reason you took the knives with you to the petrol station."

He jailed Skinner for 20 months and imposed an 18-month detention and training order on the younger boy.