This is what she wrote in an open letter to the Chairman of Beckenham Conservative Association:
It has been my pleasure and privilege to serve as Beckenham’s Member of Parliament for nearly 12 years now but, with the prospect of a Conservative government after the next election, I have for some months now been considering whether it might be time for me to move over for a younger person. Indeed, I first mentioned that I was thinking about retirement to the Chief Whip in March this year.
Given the probable timing of the next General Election, I thought it only fair to the constituency to come to a final decision over the summer months.
I am therefore writing formally to confirm my intention to retire at the General Election, now expected in 2010. Not only will the new Beckenham constituency be able to move into the exciting years ahead with a younger and refreshing new candidate, but I will be free to take up new challenges while still of an age to contribute fully to the future of our country.
I will obviously remain an active MP until the dissolution of this Parliament and I look forward to working with new candidate for Beckenham over the coming months.
I would like to thank you and all officers and members of the Association for their active support and kindness to me as MP and to Peter and I look forward to being able to thank them more personally in due course.
Jacqui has always been hugely supportive to me and has given me invaluable advice both before and since the GLA elections. She is greatly respected both at Westminster and locally and I know she will be missed.