If treated solely as 'speeding', the penalty is 6 points plus a fine of perhaps £500 (plus a £15 'victim surcharge', plus costs of perhaps £80) and a ban of perhaps 2 months:
http://www.pepipoo.co...trates_guidelines.htm
(The highest fine for speeding which I've seen reported in our local press was £850).
If, as is possibly more likely, it's treated as 'dangerous driving' then it's a one year ban plus a fine (probably as above but theoretically unlimited) plus costs and the victim surcharge.
Chris