In December 2003, she was appointed Minister of Canadian Heritage by the new prime minister, Paul Martin. In the 2004 election, she was defeated by Roger Clavet of the Bloc Québécois, and replaced as heritage minister by Liza Frulla a month later.
On August 18, 2004, it was announced that she was to become Paul Martin's principal secretary, replacing Francis Fox. She held this post until the defeat of the Martin government in 2006. She ran again in that election, this time placing third behind Clavet and winner Luc Harvey.
|Parliament of Canada|
| Member of Parliament for Louis-Hébert
|27th Ministry – Cabinet of Paul Martin|
|Cabinet post (1)|
|Sheila Copps||Minister of Canadian Heritage