Across the UK this was the period when the two-party system was reshaped. The Labour Party extended its presence beyond the industrial regions and big cities to replace the Liberals as the main opposition to the Conservatives. In Cornwall things were different. Labour grew but was unable to dislodge the Liberals and a three-party system survived, even in the Labour ‘landslide’ of 1945. Although Labour won its first Cornish seat at Penryn and Falmouth in that year, it still polled (slightly) lower than the Liberals and much lower than its level in England. Meanwhile the Tories picked up four of the five Cornish seats, as their opponents split the vote. As late as 1929 the Liberals had won all five Cornish constituencies but that proved to be the last election until 1997 in which the Tories did not win most votes in Cornwall and (with the exception of 1966) most seats.
The five parliamentary constituencies in this period were somewhat different from the consistent pattern between 1950 and 2010, in which year Cornwall gained an extra, sixth seat. In the east Bodmin and North Cornwall were fairly similar to the two eastern seats of the later twentieth century. In the far west St Ives was also not that different from its later namesake. The differences lay in between. The Camborne constituency of this period was restricted to Camborne-Redruth and Hayle plus the rural areas immediately to the south and east. Penryn and Falmouth was a misnomer, as this constituency stretched eastwards along the coast to include Truro and the St Austell district.
Here are the detailed results by constituency.
Cornish studies resources 