Gareth Thomas has replaced Roberta Blackman-Woods as shadow civil society minister.
Thomas, 44, is a Labour and Co-operative Party politician who has represented Harrow West since 1997, when he was 29 years old.
He was a minister of state at the former Department for Business, Enterprise and Regulatory Reform and at the Department for International Development under the last Labour government.
He held the shadow brief at DFID after last year’s general election, before becoming shadow minister for higher education and science until his latest appointment.
Thomas, a former teacher, has chaired the Co-operative Party, which supports cooperative principles, since 2000. Twenty-nine MPs currently stand on behalf of it and Labour.
Thomas has degrees in economics and history and served for seven years as a councillor in the London borough of Harrow, where he has lived all his life.
He is a former parliamentary private secretary to Charles Clarke and his hobbies, listed on his website, include running, rugby union and supporting Arsenal FC.
Blackman-Woods has moved to shadowing the Communities and Local Government department, although her precise role has yet to be confirmed.
Thomas’ appointment follows that of Jon Trickett as shadow minister for the Cabinet Office last week. Trickett, MP for Hemsworth in West Yorkshire, replaced Tessa Jowell.
In a statement about Thomas' appointment, Trickett said: "Gareth brings a breadth of experience to this important job. Having been a long-standing and experienced minister, he knows how Whitehall works and also has an in-depth understanding of the issues and challenges facing the third sector."