Since 1945 the Liberals/LibDems have won 30 by-elections. (This includes five which were defences of seats already held – Montgomeryshire, Truro, Cheadle, Winchester and Eastleigh.) Which was the most important victory?
Four possible measures of importance could be analysed:
1) Swing - the percentage change in votes cast at the by-election
2) Durability - the number of years the seat was subsequently continuously held
3) Political importance of the winner - the positions held by the winning candidate
4) Changing the political narrative - the political and media reaction to the victory.
The top 3 victories on each measure would be:
Top: Bermondsey 1983 (44.2%), Second: Christchurch 1993 (35.4%), Third: Sutton and Cheam 1972 (32.6%)
Durability of Victory:
Top: Roxburgh 1965 (49 years), Second: Berwick 1973 (41 years), Third: Bermondsey 1983 (31 years)
Importance of Winner:
Top: Roxburgh (David Steel, party leader), Second: Bermondsey (Simon Hughes, deputy party leader, party president), Third: Berwick-upon-Tweed (Alan Beith, party deputy leader)
Changing the political narrative:
This last category is rather subjective, but both Orpington and Eastleigh gave a severe jolt to the Conservative Party’s confidence about winning the next election and both demonstrated that the Liberals/LibDems are more resilient than many people believed. Torrington was the first of the Liberal post-war victories, but the seat was only held for one year, until the Conservatives won the 1959 election and regained the seat. Eastbourne in 1990 came at a time when the LibDems were struggling. It gave a significant boost to party morale and credibility and hastened the demise of Margaret Thatcher.