This is the text released to her constituents by the Brent (Greater London) constituency office:
In just over a week's time, I shall reach the tenth anniversary of my election to Parliament in the Brent East by-election. I took some time off this summer and found myself reflecting a great deal on the last ten years.
It has been an enormous privilege to serve as an MP in Brent. Indeed, for me personally, so much of the last decade has been both rich and surprising. I am not sure that I would ever have expected to be elected so young, and I certainly never expected that I would have had the opportunity to serve in Government.
The greatest privilege of my work both as a constituency MP and as a Minister has been the gift of being able to share in the private joys and struggles of so many people's lives - many different from one another and very different from my own. I shall always be inspired by the profound courage and dignity I have witnessed in people I have worked with, often in the face of the most extraordinary difficulties.
Of all my parliamentary work, the campaign I remain most proud of is the campaign to get my constituent released from Guantanamo Bay. I shall always count the moment my constituent walked back in through his own front door and picked up his five year-old daughter for the first time in her life as one of the most precious of my life.
In Government, the moment I count as my proudest is the one where I listened to Nick Clegg announce our intention to end the routine detention of children in the immigration system - something I worked hard to deliver, in what, at times, felt an almost insurmountable battle with the Home Office. I feel humbled too to have been able to play my part in delivering the pupil premium to schools and to extend free early education to two year olds, and perhaps the work dearest to my heart, that of reforming the system of support for children with special educational needs.
There have been so many rewards to this work -- too many to list here. But having taken the summer to reflect on the future, I feel now that at the General Election, the right time will be right for me to step aside. I wanted to explain why I have decided not to seek re-election in 2015.
I first joined the party almost exactly twenty years ago, during fresher's week at university. It was then -- and still is now - absolutely inconceivable that I could ever join any other political party. As with most party members, there have always been a few issues where I have disagreed with party policy. But over the last three years, what has been difficult is that policy has moved in some of the issues that ground my own personal sense of political vocation - that of working with and serving the most vulnerable members of society. I have disagreed with both Government and official party lines on a whole range of
welfare and
immigration policies, and those differences have been getting larger rather than smaller. Disagreements with the party on other areas of policy I have always felt could be managed, but these things are just core to my own sense of calling to politics. I have tried hard to balance my own desire to truthfully fight for what I believe on these issues with the very real loyalty and friendship I feel to party colleagues, but that has created intense pressure, and at times left me very tired. I don't think it is sustainable for me personally to continue to try and do that in the long term.
I want to reassure people in Brent that I shall continue to work very hard to represent them over the next 18 months until the next General Election. My constituency office will remain open five days a week, just as it has always been. I shall be out campaigning for the local elections with my local LibDem team over the forthcoming months and will campaign to get my Liberal Democrat successor elected to Parliament in the General Election. In Parliament I shall continue with my work as Chair of the All Party Parliamentary Group on Refugees and will carry on making the case for a fair and humane immigration system as Parliament considers a new immigration bill in the coming months.
I hope that I have been able to support and represent the people of Brent well as their MP, but I feel rich beyond measure to have been able to do this work here. I shall always count myself indebted to those who gave me this opportunity to serve - to the thousands of constituents who voted for me and to the many Liberal Democrat supporters and members who campaigned and walked the streets for me over three elections. I hope that, over the last 10 years, I have at least gone some way in repaying the faith that so many have shown in me.