A MOTHER and her baby son are lucky to be alive after a tractor and trailer landed on top of their car in a horrific crash near Chippenham.

The 33-year-old, of Christian Malford, was driving along the A420 in her blue Ford Focus estate on Monday afternoon when she collided with an oncoming John Deere tractor.

Her one-year-old son, who was strapped into a child seat in the back, was pulled out and taken to hospital suffering from a broken nose. By removing the roof and dashboard of the car in a frantic two-hour rescue operation, firefighters were able to free the woman, and she was airlifted to the Royal United Hospital in Bath.

She is now in a critical condition at Bristol's Frenchay Hospital, where she is being treated for serious head injuries and broken legs.

The tractor, which was towing a trailer carrying scrap metal, was travelling from Wick, Bristol. The 18-year-old driver was unhurt.

Just before 2pm, emergency services were called to a stretch of the A420 at the junction with the B4039 to Yatton Keynell.

Before arriving at the scene of the accident, Wiltshire Air Ambulance picked up a doctor and nurse team from the RUH Hospital to help with the rescue efforts.

"Attempts were made to try to get the tractor off the vehicle but this didn't work," said Inspector Cavan Moroney of Melksham Police. "Fortunately, the baby was strapped into a child seat and was taken to hospital soon after we arrived.

"The woman was trapped by her ankle and was drifting in and out of consciousness.

"An elderly gentleman was following the tractor at the time and he is very shaken up."

To get the woman safely to hospital, the air ambulance was forced to land on the road. After the helicopter had flown off, police started the clean-up operation.

The road was cleared by 4.16pm.

Station office Ade Hurren, of Chippenham Fire Brigade, praised the teamwork of the emergency services.

He said: "It was excellent. We were able to create the space which the ambulance crew needed- it worked really well.

"When I arrived the woman was conscious and trapped on the driver's seat. We tried unsuccessfully to move the vehicle off and offered reassurance to the casualty until the ambulance arrived and took on that role."

Police are investigating the accident but they said it appeared that the woman, who has not been named, lost control of the car.

Anyone with information about the crash can call Corsham police's traffic department on (01225) 763101.

bpayne@newswilts.co.uk