After his graduation, he worked for some years for the Dutch foreign service, being part of the Permanent Mission of the Kingdom of the Netherlands to the United Nations (1970–1977). He then worked as a secretary to the Dutch Minister for Development Cooperation (1978–1981). In 1982, he became an elected member of the House of Representatives, where he focused on foreign and European affairs.
In 2002, Weisglas was elected Speaker of the House, after Jeltje van Nieuwenhoven of the Labour Party stepped down. He was the first Speaker of the House to be elected (and re-elected in 2003) by a democratic vote among parliamentarians without requiring royal approval.
On 15 August 2006 he announced that he would not be a candidate in the 2006 Dutch general election, ending his 24-year-old career as a politician. His last day as Speaker of the House was on 30 November 2006.[2]
