Nesbat Khan, aged 22, appeared at the Old Bailey accused of causing death by dangerous driving after she raced along Molesworth Street, Lewisham, at speeds of up to 65mph and collided with 14-year-old Benjamin Chudleigh.

In court Khan admitted she drank some wine at an office party that afternoon and felt merry on the train journey home as she had skipped breakfast and only had a sandwich for lunch.

She said after an hour at her home in Plumstead Common Road, Plumstead, she felt "normal" and drove her S-reg Mercedes 180 saloon to her boyfriend's house in Thamesmead.

She then went to pick up a friend from a bar in Lewisham.

The accident occurred as the teenager was on a pedestrian crossing on the road, which had a 30mph limit.

Khan, who worked for the accounts department for Mercedes at Piccadilly, told the court she did not see Benjamin and did not know what her car had hit until she got out.

"There was nothing I could do. If there was something I could have done I would have done it, I wouldn't have just sat back but I didn't have a chance."

Benjamin died later at hospital from multiple injuries.

The jury heard Khan had tested positive in a breath test but in a blood test three hours later she was well within the legal drink drive limit.

Miss Tapping said: "There is no guarantee at the time of the accident she exceeded the legal limit of blood alcohol reading but she had undoubtably been drinking."

No eye-witnesses saw the collision, which happened about 11pm on May 14 last year, but police experts reconstructed the accident by examining the scene and damage to the car.

In passing sentence Mr Recorder Wadworth QC told Khan: "It happened because you drove too fast and for all the figures in the tests you were the worse for drink."