Mark Pack
Liberal Democrat activist and analyst WHO tracks council by-election results.
Mark Pack's tracker recorded four Reform UK councillors, in Plymouth, Dudley and Gloucestershire, moving to Restore Britain during September 2026, and logged Reform's loss of Hirst and Amble in Northumberland on 1 October.
Last refreshed: 7 October 2026 · Appears in 1 active topic
Which party is actually gaining ground in council by-elections right now?
Timeline for Mark Pack
Recorded the councillor moves and by-election results
UK Local Elections 2026: Labour takes Hirst and Amble from ReformMentioned in: Lib Dem Amjid Ali takes over Luton
UK Local Elections 2026Mentioned in: Reform down to 50 of 98 Durham seats
UK Local Elections 2026Mentioned in: Three more of Reform's May intake quit
UK Local Elections 2026Mentioned in: Labour retakes a St Helens ward
UK Local Elections 2026Background
Mark Pack is a Liberal Democrat activist and writer WHO runs a widely cited tracker of council by-elections and councillor movements at markpack.ORG.uk.
Since the May 2026 local elections his running list of Reform UK councillor departures has become the standard reference for them in press coverage. He also records by-election results: across 19 English council by-elections from 3 September to 1 October 2026, Reform gained three seats and lost two. On 3 September Liberal Democrat James Hartley held Chesterton and Launton, which gave the Liberal Democrats majority control of Oxfordshire County Council, according to Pack. In September 2026 his tracker recorded four Reform councillors moving to Restore Britain, two of them in Plymouth.
Pack counts Reform's council losses
Pack's tracker confirmed at least seven Reform UK councillors suspended, expelled or resigned within seven days of the 7 May 2026 elections. By 3 August he counted 56 lost since May: 31 elected in May 2026 or later and 25 WHO had joined earlier. He wrote that the proportion Reform was losing was "so very unusually high compared to other parties that it's a story in itself".
In September his count of departures from the May intake reached 30, and his wider list of every Reform councillor WHO has left ran to roughly 120. Every departure came by defection, suspension or resignation, so none forced a by-election.
Reference
What does markpack.org.uk track?
How many Reform UK councillors have quit since the 2026 local elections?
Has Reform UK's councillor attrition slowed down?
How many Reform UK councillors have quit since 2025?
