My wife was in the third car of a five car accident over a year ago. Our car was written off. We believe that the car at the back was responsible for the accident and evidence points to that. However, the driver of the car we were pushed into is making a legal claim against us. Our insurers' solicitors have entered a defence on our behalf, and say it may be necessary to settle the matter on "Best Terms" and want us to sign a Form of Authority to admit liability.

Is this normal procedure?