There is a web site called Lawtel, where you can type in your injuries etc and it will bring all case law and case settlements similar to your injuries.
Ie if you log on and find one person was offered �2000 and another was offered �2500 and you were offered �1000, you could print off and send in the info from Lawtel and ask them to reconsider their offer.
If you have a solicitor acting on your behlaf they should do this for you, and to be honest i work in personal injury claims and if a client writes direct to us, they get offered a lot less than what they would if they were being represented by a solicitor.