In her letter to the Prime Minister, Norwich North MP Chloe Smith said:
I have been privileged to serve my country and my party under your leadership.
However, for the remainder of the Parliament I want to be able to spend more time serving my constituents. My constituents have always come first for me, and they know the high standards and hard work that I ask of myself as the Member of Parliament for Norwich North.
As you know, I was only 27 when I was lucky enough to be elected as an MP, and of my four years in Parliament so far, I have spent three as a minister.
Liberal Democrat Michael Moore has been replaced as Scottish Secretary by the party's chief whip Alistair Carmichael.
This is not going to be a Conservative Cabinet reshuffle, but among the junior ranks there will be some tinkering.
Chloe Smith was just 27 when elected MP in Norwich and became David Cameron's youngest minister when she was promoted two years later.