Poulsen was first elected into parliament at the
2001 Danish general election. On 23 February 2010, he was appointed as Minister of Taxation, while
Karen Ellemann took over the Ministry of the Environment. On 8 March 2011, he was appointed
Minister of Education, following
Tina Nedergaard's resignation on the same day. In late 2011, he became the center of a dispute regarding the disclosure of confidential documents in favor of discrediting the former Danish prime minister,
Helle Thorning-Schmidt and her husband
Stephen Kinnock due to their tax relations. The affair happened in the
2011 Danish parliamentary election and involved the head of SKAT (the Danish tax agency) Copenhagen (Erling Andersen), the Permanent Secretary of State in the Ministry of Taxes, Peter Loft, and the
spindoctor of Lund Poulsen, Peter Arnfeldt. On 28 June 2015, he was appointed Minister of Business and Growth in the government of Lars Løkke Rasmussen II. On 28 November 2016, he was moved from here to the position of
Minister of Employment. He was appointed minister of economic affairs on 15 December 2022 when
Mette Frederiksen presented her second cabinet. On 6 February 2023, he became acting minister of defence while
Jakob Ellemann-Jensen was on leave. On 22 August 2023, the appointment became permanent. On 23 October 2023, he replaced Ellemann-Jensen as
Deputy Prime Minister after his resignation as party leader of Venstre. He was elected leader of Venstre on 18 November 2023, with Stephanie Lose taking over as minister of economic affairs. On 9 February 2024, he stated, "Denmark should speed up its military investments after new intelligence indicates that Russia is rearming faster than expected and that it could attack a NATO country within three to five years". On 3 April 2024, he fired
Chief of Defence Flemming Lentfer, saying that Lentfer had failed to keep him informed about weapons failures on board
HDMS Iver Huitfeldt when it fought in
Operation Prosperity Guardian during armed combat against
Houthi militants. In 2025, the
Auditor general criticised him, and previous ministers, for inadequate security at 18 military bases. == Personal life ==