Simplify the following text for a Grade 11 native English-speaking person.
Original: He was the leader of the Conservative Party from September 2001 to November 2003 and is the Member of Parliament ( MP ) for the constituency of Chingford and Woodford Green .
Simplified: He served as the Leader of the Conservative Party from September 2001 to October 2003 . He is currently the Secretary of State for Work and Pensions in the Cabinet of David Cameron , and a Member of Parliament ( MP ) representing the London constituency Chingford and Woodford Green .