A dopey London bus driver who drove through the morning rush hour while high on pot has escaped jail.

Sarfraz Khan, 28, was caught after an inspector found his double decker reeked of weed.

Khan failed a series of tests but explained it was due to the cold weather and the fact he was ‘not that good at balancing on one foot.’

He said he might have eaten a spiked hash cookie five days before but was found guilty of driving while unfit at City of Wesminster Magistrates’ Court.

Khan, who received a police caution for cannabis possession in 2003, was suspended from work after the incident but offered his resignation following his conviction.

District Judge Michael Snow earlier warned he faced a ‘deterrent sentence of imprisonment’ but today suspended his 12-week jail term for 12 months.

Khan was driving a number 30 double-decker to Hackney when he was pulled over in Gloucester Place, just off the Marylebone Road in central London on November 27, 2009.

Inspector Alan Matthews, who boarded the bus at around 8.50am, said he instantly noticed the smell of drugs on the bus.

Mr Matthews told the court: ‘I noticed straight away an odour, which from past experience, I knew to be the smell of cannabis.

‘It is hard to put a level on it but it was a noticeable odour.

‘I approached the driver and told him of my observations and I looked at the driver and he had a fixed stare periodically and animated movements.

‘As I could smell this odour and from looking at the driver I believed he may be under the influence of cannabis and I asked my colleague to call for police assistance.’

The police were called and Khan was swaying so badly he failed four out of five elements of a roadside drug test.

Cannabis was later detected in his blood.

Khan said: ‘I’m not good at balancing on one foot anyway, but if anything was going to make it worse it’s the weather.

‘After the arrest I was found there was cannabis in my blood and realised I had been to a house party about four or five days earlier where there was some food being distributed and which I consumed.

‘There was a cake and that’s where the cannabis came from.’

Khan is currently unemployed, living off benefits as he attempts to find security work, and as well as a two-year-old son is expecting the imminent birth of his second child within the next fortnight.

Imposing a 12-week jail sentence suspended for a year, 100 hours of unpaid work and a two-year driving ban, Judge Snow said bus drivers accepted a ‘grave responsibility’.

He said: ‘On one level I accept that there is no evidence before me that your driving was impaired beyond a moderate level.

‘But against that you were working as a bus driver, driving a double-decker bus in central London in rush hour, with passengers and where you were liable to pick up children.

‘You were endangering an awful lot of people in a serious way by deciding to drive with cannabis in your system.

‘The sentence is 12 weeks imprisonment, however because of your lack of previous convictions and family situation I am prepared to suspend this for 12 months.’

Khan was also ordered to pay £750 towards prosecution costs.

The driver, of (27) John Barnes Walk, Stratford, east London, had denied a charge driving while unfit to do so through drugs.