Bannerman hoped to enter Parliament at the 1806 general election, but despite being prepared to spend £2,000 on a campaign, he failed to find a seat. However, a vacancy was created in early 1807 the resignation of Josias du Pre Porcher, MP for the pocket borough of Bletchingley which was then under the patronage of Rev. Jarvis Kenrick, and Bannerman was returned at the by-election in January 1807. He hoped to find a Treasury borough at the general election later that year, but was unsuccessful.[2]