Link , Link , Link , Link , Link , [Marjory LeBreton worked with four leaders of the Progressive Conservative Party of Canada - John Diefenbaker, Robert Stanfield, Joe Clark and Brian Mulroney - from 1962 to 1993 before being appointed to the Senate on the advice of Mulroney. She sat as a Progressive Conservative Senator from her appointment until moving with most of her caucus colleagues to the new Conservative Party of Canada in 2004, of which she was soon elected to Chief Whip. She served as an advisor to then opposition leader Stephen Harper during the 2006 election, which the Conservative Party won. After the election, she was named to the cabinet position Leader of the Government in the Senate. On July 4, 2013, LeBreton announced she would not continue in the position as of the next cabinet shuffle, which occurred later that summer. She retired from the Senate upon reaching her 75th birthday on July 4, 2015.]