Jansen was also on place nine on the party list for the 2019 Dutch Senate election, but the PVV received only five seats. In October 2019, MP Sietse Fritsma stepped down to start a business, resulting in Jansen becoming a member of the House of Representatives. Jansen was sworn in on November 27, 2019, and he indicated that he planned to resign from his other political positions. Two people were in front of Jansen in the line of succession, Karen Gerbrands and Robert Housmans, but both turned down the position; Gerbrands had resigned from the position of MP the year before and had criticized the party, and Housmans refused because he had recently become a member of the provincial-executive of Limburg. In the House of Representative, Jansen is the PVV's spokesperson in the area of health care together with Fleur Agema. When the first cases of COVID-19 were confirmed in the Netherlands during the 2020 pandemic, Jansen criticized the government for not taking enough precautions to stop the virus. He pointed at the fact that other European countries had taken more action and said Minister for Medical Care Bruno Bruins should think ahead instead of solely listening to experts. Besides, he accused the cabinet of withholding possible scenarios. His municipal positions included creating more housing, increasing the quality of education, and making sports more accessible. During his political career, he has also opposed Islamization and the construction of new mosques in Almere, and he has said he would like the government to revoke passports of criminal immigrants with multiple citizenship. Jansen has also objected to some forms of or increases in government spending; he has opposed proposals to increase cultural subsidies in Flevoland, was against spending €470 million on the development of Nieuw Land National Park, and has criticized environmental subsidies leading to the construction of many windmills in the province. He has acknowledged the existence of climate change, but called it a natural process that has been going on throughout history and has denied human activity as a major cause. Jansen has also called measures to address climate change including the energy transition too expensive. Furthermore, he has asked for more transparency in the public financing of the exposition Floriade 2022, planned to be held in Almere. He has also accused the municipality of including part of the event's costs in other proposals to make the total costs seem smaller. Jansen is married to his wife, and they have two children. According to his party profile, he has been living in Almere since 1998.