Lauren Harrison told a court she was bursting for the toilet when she came to the attention of officers as she raced over the White Cart Viaduct, near Glasgow airport, last October.

They started tailing her as she drove at nearly 90-miles-per-hour, racing from her work in Govan to her Kilmacolm home.

Paisley Sheriff Court heard that officers decided to pull Harrison over when she slowed down to take the slip road off the A737 which leads into Johnstone.

They put on their blue flashing lights and turned their siren on, bringing Harrison’s vehicle to a stop just next to the slip road.

And, when they approached her Volkswagen Golf Plus, she apologised for speeding, telling the officers she needed the toilet.

Sheriff Craig Turnbull was told that the only time Harrison dropped her speed below 87-miles-per-hour after they noticed her speeding on the White Cart flyover was when she slowed down to take the Johnstone slip road.

The officer who pulled Harrison over said he was most concerned about her speed and the manner of her driving, adding that she was doing nearly 90-miles-per-hour and the roads were wet.

He said he knew that it takes 97m to come to a stop when a car is traveling at 70-miles-per-hour, adding: “If someone were to break the driver wouldn’t have stopped in time. She was traveling too close to the cars in front – her stopping distance wasn’t sufficient. Her driving was dangerous.” The court heard that a handful of vehicles had to move out the road to let Harrison passed in her vehicle while officers tailed her in their Vauxhall Astra, which was seven or eight car lengths behind.

Giving evidence in her own defence Harrison, who was recently made a managing director of a shipping and marine consultancy firm, said she had been working that day, taking the members of her team to the cinema to see a film.

The 30-year-old – who has been driving for 13-and-a-half years – said that, after the film, she went to Braehead’s Intu shopping centre to pick up a baby gift for a friend who had recently given birth, before traveling on her daily route back to her home in Kilmacolm.

She said she paid no particular attention to her drive home as it was just an ordinary journey and disagreed with the officers’ claim that the roads were wet, saying it was a clear day and that the roads were dry.

She said it was about 9pm when she was heading along the A737 and that she had indicated when she had been changing lanes on the road, explaining: “I’m sure I did – I really don’t like drivers that don’t like indicating.” She also denied “tailgating” other vehicles, adding: “I maintain I didn’t and I wouldn’t. It’s not my driving style.” Harrison, who is originally from England, said she was very talkative with the officers, telling the court she was trying to find out the difference between the procurator fiscal service and the Crown Prosecution Service – the prosecuting authority in her home country.

She added: “I didn’t know what the fiscal was. I’ve never had anything to do with the police.

“I needed the toilet but it’s not a reason to go fast.

“I accept I was doing over 60-miles-per-hour but I wasn’t going at the speeds they stipulated.

“I travel extensively for work, I do between 20 and 30,000 miles a year. I need my car so wouldn’t risk it.” She told the court she “probably annoyed” the officers with the amount of questions she asked them while they spoke to her next to her Golf Plus, which she described as being like a Range Rover Evoke.

Sheriff Craig Turnbull told Harrison: “Your driving fell below that expected of a reasonable and competent driver.” But he chose not to convict Harrison of dangerous driving, instead finding her guilty of the lesser charge of driving without due care and attention.

As he did so he said it was “borderline”, adding: “It was close to be honest but having considered the evidence and the circumstances I’m persuaded just and no more.” He fined Harrison, who lives in Kilmacolm with her partner, £1000.

Harrison was given 28 days to stump up the cash and had eight penalty points placed on her license.