Katie Price today blamed being a "typical woman driver" for veering into another lane on a busy road while driving her new pink horsebox.
She is accused of causing two other vehicles to move away as she drifted into their lane on the A23 at Bolney in West Sussex at 11.55am on February 19.
Prosecutors said the 32-year-old model was seen on the phone for two to three seconds by two officers after they drove alongside her in a patrol vehicle following the "careless" manoeuvre.
Giving evidence at her trial, Price denied using her phone behind the wheel, insisting she had no reason to because the horsebox was equipped with handsfree bluetooth equipment.
Asked by prosecutor Rachel Beckett why she veered, she told Mid Sussex Magistrates' Court in Haywards Heath: "Because I'm a typical woman driver.
"I'm just not used to a lorry that big. I was probably a bit scared because it was on a motorway.
"I don't remember veering but it is quite difficult."
Price was among eight people, including four adults and four children, travelling to Eurodisney in the vehicle, which she had driven only twice before.
She told the court everyone was in an "excitable mood" and they had shortly left a petrol station to buy sweets and refreshments for the journey when she was pulled over by police.
Asked how easy the horsebox was to drive, Price replied: "It's massive. It's not that easy. It's quite a big vehicle, it's like a boat."
She told police in a statement that she may have been spraying perfume at the time when she was apparently seen using her mobile phone behind the wheel.
"I'm quite OCD," she told magistrates. "All my friends know that I'm always spraying perfume. I'm obsessed with it."
Price, who the court heard has seven points on her licence, denies not being in proper control of a vehicle.
Price was shown a copy of her mobile phone bill showing no calls were made around the time when she was pulled over.
The last call was made at 11.15am and after that a text message was recorded at 1.03pm on her gem-encrusted BlackBerry which she said was bought in the US.
When she was pulled over, Price said Pc Mann told her: "Oh, it's you again."
She said he had previously pulled her over and added: "If I'm honest, he was a bit cocksure.
"I just wanted to get on. I remember saying: 'Oh, here we go again'. I'm always getting pulled over."
Ms Beckett told her: "I suggest you were using some sort of device."
Price replied: "No."
She went on: "It was just a general mistake. I don't think it was that bad to be honest.
"I'm in a big lorry and I'm just getting used to it. I was over but I wasn't over 50% as I've been told."
For most of the hearing Price, dressed in a fur-trimmed coat and black leggings, sat behind her lawyer, Nick Freeman, nicknamed Mr Loophole, as Mr Reid - who was a passenger in the vehicle when police stopped it - sat outside the courtroom.
Pc Phill Mann, of Sussex Police, told the court that he saw Price making a texting motion on a touchscreen-type handset before pulling her over.
The court was shown police footage apparently showing Price veering slightly across the carriageway while at the wheel of the luxury 7.5 tonne horsebox which has a capacity to hold 16 people.
Ms Beckett said the officers saw the distinctive vehicle on the A23 at a location known locally as Jeremy's Corner.
She said: "Pc Mann observed a vehicle which he saw drifting slightly into lane two from lane one.
"Pc Mann drove up next to the vehicle and saw Miss Price was driving and saw that she was using a mobile phone.
"When the defendant saw the police car, she held the device down. Pc Mann's colleague, PCSO (Edward) Mitchell, also saw Miss Price using the mobile phone for some two to three seconds."
When Price was pulled over, she told Pc Mann that they might have seen a perfume bottle and not a mobile phone, the court was told.
She retrieved a large bottle of perfume from a bag and showed it to Pc Mann, who told her that it was not what had been seen in her hand moments earlier.
Ms Beckett said Price also showed the officer her mobile phone covered in coloured stones.
Pc Mann told the court: "I saw a person who I know to be Katie Price in the driver's position and in her right hand she had what appeared to be a mobile phone.
She had her thumb on the phone, and appeared to be texting. It was slim, black and palm-sized, like an iPhone. I think that's what I saw."
As soon as she saw the police alongside her, she put the item down and slowed down before being pulled over with blue flashing lights, Pc Mann added.
He cautioned Price and told her she would be reported for using a mobile phone while driving and driving without due care and attention.
Describing her driving as "careless", Pc Mann said: "I believe she said that she wasn't using her mobile and that she was using perfume.
"She leaned back into the back of the cab and pulled a large bottle of perfume out of a large zip bag.
"I said that wasn't the item I had seen. She got her phone out of the same bag and showed me that and said, 'Was it that?'.
"I couldn't recall whether that was the same one I had seen. It had coloured gemstones on it. That's not what I had seen in her hand."
Pc Mann said he reported her before allowing her on her way, with Mr Reid sat in the front passenger seat.
During cross-examination, Mr Freeman said Pc Mann's assertion that the horsebox had taken up 50% of lane two was a "gross exaggeration and you are mistaken in that fact".
Mr Freeman suggested to the officer that the drifting was typical among drivers and happened "quite regularly" on the road.
He also cast doubt on Pc Mann's claim that Price had been seen with a slim black phone, saying the gem-encrusted phone she produced for the officer was the only one she had.
"I suggest to you that your description was totally inaccurate to the extent that she didn't put anything down, she just pulled over," Mr Freeman told the officer.
Pc Mann replied: "I saw her hand drop to her right-hand side."
PCSO Mitchell said he immediately knew who the horsebox belonged to after seeing it on television.
He said: "I looked at the vehicle and saw Miss Price who I believe was texting on her phone.
"She was looking down at her phone pressing the phone with her right hand. She was texting or dialling a number. My view was very good."
He said he told Pc Mann what he had seen and they decided to pull her over.
PCSO Mitchell stayed in the patrol car while Pc Mann went to question Price because "he had more powers".
The case was adjourned before lunch after Mr Freeman put forward a submission that the proceedings were "defective".
He argued that Price should not be convicted because she was told at the time that she was being reported for using a mobile phone while driving and driving without due care and attention.
Mr Freeman said she was not told either at the time or within 14 days afterwards that she would be summoned to court for not being in proper control of a vehicle.
Ms Beckett said it seemed an "absurd" submission that, because the officer did not list the possible offences she could be charged with, the proceedings were defective.