 The MR purchased a swathe of land from Gonville and Caius College, Cambridge along the planned route, and Parliamentary approval for the branch was granted in 1912.The project was hampered by disagreements with the Watford Borough Council and by the outbreak of World War I in 1914, and construction of the branch did not begin until 1922.The MR experienced difficulties running the line across the River Gade and the Grand Junction Canal, and this pushed costs up to £300,000.