Mum Sarah Jenkins was reversing the car off the driveway at Old Stocks Court in Upper Basildon when a section of block paving gave way at 8.15am on Wednesday.

The rear wheels of the silver Mercedes ML250 lurched backwards and sank into an eight foot deep crater which had opened up across an eight foot wide stretch of saturated ground, leaving the car just inches away from the exposed gas pipe.

Mrs Jenkins, who has lived at the house with her husband Vaughan since it was built 12 years ago, was setting off to take their three children to St Andrew’s School in Pangbourne, where the Duchess of Cambridge and her sister Pippa were pupils.

She said: “The back of the car just disappeared and I was panicked. At first I thought I had hit something, so I turned and saw the kids sitting at an angle.

“We all jumped out of the car straight away and I called the police. All I was doing was making my way to take the kids to school, as usual.

“The police have been amazing and very helpful.”

Neighbours let Mrs Jenkins and her children take refuge as police cordoned off the driveway, while engineers from Southern Gas Networks were called in to check that the pipe had not fractured.

Southern Gas Networks spokeswoman Claire Buchanan confirmed no gas leaked from the pipe and added: “We were called by the emergency services because ground movement had exposed a gas mains pipe.

“We will be staying on site to carry out checks, as standard procedure, on the mains pipe once the car has been removed.”