From your profile I see that you hold a BEng, the requirements post 1999, now require four years of academic study rather than three for chartership, in other words to meet the Engineering council academic requirements you will require a MSc, or sit the equivalent level Engineering council exams. I forget the experience requirements, but it use to be either 2 years on a structured graduate training scheme, or 5 to 8 years experience with a position of supervisory responsibility. To be truthful although OM15 stated some examples it is not really that important to gain chartership, I have fared quite happily without it; but most contractors (including myself) have never needed chartership. £26 a year, OM15 I may be wrong but I thought it was more like £260 a year.
Depends if you want to climb up the corporate ladder then it may be necessary, but if you wish to remain a technical specialist and proceed down the contract route ,your experience is the thing that will count, having CEng wont really make that much difference.