Spending a fortune to do so, VanKoughnet entered politics in 1856. During his campaign, he expressed the belief that the ownership of Rupert's Land and the North-Western Territory should be transferred from the Hudson's Bay Company and that they should become part of the Province of Canada. Following the resignation of Sir Allan Napier MacNab he was named President of the Executive Council of the Province of Canada and Minister of Agriculture in the administration of Sir Étienne-Paschal Taché; he was elected to the Legislative Council of the Province of Canada for the Rideau district later that same year.