Shami Chakrabarti, director of human rights group Liberty, has been made a CBE in the Birthday Honours.
Ms Chakrabarti has been a thorn in the side of the government
The 38-year-old says she regarded the award as an invitation to keep fighting for civil liberties.
A barrister, she worked as a Home Office lawyer for five years, giving her a unique insight into targeting the government where it hurts.
Ms Chakrabarti, is a constant critic of what she describes as the government's constant erosion of personal freedoms.
She has been particularly critical of outgoing Home Secretary, John Reid.
Ms Chakrabarti, who has been director of Liberty for four years, said: "I'm not exactly the most predictable choice, no-one was more surprised than me.
"I hope it will send a timely signal that democratic dissent is not disloyalty, it is a positive civic duty.
"This is an official Royal invitation to do more, and I will take that invitation on behalf of people punished without trial and barred from protest in Parliament Square.
"This recognition belongs to Liberty, the oldest rights and freedoms campaign in this country."
Married with one son, she was educated at the London School of Economics and called to the Bar in 1994.
Ms Chakrabarti is also part of an independent commission chaired by former Nato chief Lord Robertson and ex-Lib Dem leader Lord Ashdown set up to devise a new security strategy for Britain.