The by-election was caused by the elevation to the peerage of the sitting Liberal National Member of Parliament (MP) Walter Runciman.
He was President of the Board of Trade from 1931 to 1937 but was replaced in the reshuffle which took place after Neville Chamberlain took over as prime minister from Stanley Baldwin[1] and sent to the House of Lords in compensation.
The former Liberal leader, Herbert Samuel, (now in the House of Lords) was reported as marking his return to active politics by speaking at Penzance on 11 June and the current leader Sir Archibald Sinclair, Sir Francis Acland and Foot's son Dingle Foot MP all set early speaking dates for hustings meetings.
[11] Unsurprisingly Isaac Foot and his supporters found room to attack the government on foreign policy, appeasement, the economy and international trade.
Foot was outraged at the British government's failure to stand up to fascist assaults abroad,[13] by the Japanese in Manchukuo, in Spain during the Civil War, by Mussolini in Abyssinia, and by the rise of Nazi Germany.
Reinforcing Foot's concerns, Herbert Samuel, in his speech at Penzance, said the most urgent need of the day was to restore and enlarge the authority of the League of Nations, underlining his party's belief in the policy of collective security.
The St Ives contest was reported as the most likely of a spate of recent by-elections in every kind of constituency to distinguish itself from a pattern of steadfast support for the government.
The party leader, Sir Archie Sinclair, believed St Ives and another good by-election performance by the Liberals at North Dorset on 13 July, represented a turning of the tide.
[18] Lord Crewe wrote to The Times expressing disappointment at the paper's failure to recognise the importance of the rise of the Liberal vote in a number of by-elections and the encouragement which such results were giving to the party faithful.
What the result did confirm however was that West country Labour voters would support an independent Liberal against a National candidate where their own party was not fighting, or had no realistic chance.