She was appointed Minister of Culture in Prime Minister Anneli Jäätteenmäki"s cabinet in 2003. After the resignation of Jäätteenmäki, Karpela went on to serve in the same post under Prime Minister Matti Vanhanen. She was also a supporter of the 2005 amendment to the Finnish Copyright Acting and Penal Code, which has been nicknamed Lex Karpela due to her acceptance of what many perceive to be a highly controversial addition to the Finnish law.
In March 2010, Karpela announced that she is no longer pursuing a parliamentary career following the 2011 parliamentary elections.
Prior to her political career, she also became famous for her work as an underwear and lingerie model. Karpela was elected to parliament from the Electoral District of Uusimaa in 1999, representing the Centre Party. Karpela is a convicted drunk driver and since entering politics, she has become most famous for her relationships – she has remarried twice and broken off a third, separate engagement.
Karpela"s Centre Party was in opposition and Niinistö was considered the second-most influential man in government.
She was a Member of Parliament from 1999 to 2011 and served in the government of Finland as Minister of Culture from 2003 to 2007.