We’re adding the results of more than ten thousand council by-elections.

Rallings/Thrasher have been collecting and commenting upon these results since the early 1980s. Following encouragement from Cris Derby, then editor of Local Government Chronicle we began a regular column in July 1983. More recently, we’ve written a regular column for Local Government First which is read by councillors and chief executives in England and Wales. We’ve also used these data to build the Sunday Times’ model that estimates support for political parties and to forecast likely gains and losses in successive rounds of local elections.

We’re sure that there’s much more that can be done with these data and look forward to what others will do with them. You can access the data here and an explanatory note here.

Some caveats. We like to think that the file is complete and accurate but realistically, it’s neither. For one thing we have never stored the names of candidates, just party, votes, turnout and the headline result. It was hard enough getting those when we started compiling the data and so we didn’t bother with names. When we consolidated our databases in the late 1980s a number of by-elections were lost in the digital ether. The archaeologists among you may want to try and track them down. There is a fair chance that some uncontested by-elections are also missing. We are talking a long time ago – pre-Internet – one had to write/telephone a local authority for its election results. We also stopped collecting by-elections from Scotland after they moved to STV/AV for council elections but others sources for those are probably available.

There are certain to be errors in the file. Mistakes happen. Ward names may be incorrect. Party labels may be wrong – particularly when the Alliance was in full flight during the 1980s and were fighting as SDP/Lib or Lib/SDP. Cut us some slack, please. If you do use the file, and we sincerely hope you do, then please read the explanatory note carefully before getting in touch with us – contact details on the front page.

The Table below has details and summaries of by-elections conducted from May 2015. Each spreadsheet begins with by-elections held simultaneously with each year’s main May elections and ends the following April.

2017-18 2016-17 2015-16
2019-20 2018-19