30 April 1997: The clock stopped 24 hours before the general election, and stopped again three weeks later.[23]
27 May 2005: The clock stopped at 10:07 p.m. local time, possibly because of hot weather; temperatures in London had reached an unseasonable 31.8 °C (90 °F). It resumed, but stopped again at 10:20 p.m. local time and remained still for about 90 minutes before resuming.[23]
29 October 2005: The mechanism was stopped for about 33 hours to allow maintenance work on the clock and its chimes. It was the lengthiest maintenance shutdown in 22 years.[24]
7:00 a.m. 5 June 2006: The clock tower's "Quarter Bells" were taken out of commission for four weeks[25] as a bearing holding one of the quarter bells was damaged from years of wear and needed to be removed for repairs. During this period, BBC Radio 4 broadcast recordings of British bird song followed by the pips in place of the usual chimes.[26]
11 August 2007: Start of 6-week stoppage for maintenance. Bearings in the clock's chime train and the "great bell" striker were replaced, for the first time since installation.[27] During the maintenance works, the clock was not driven by the original mechanism, but by an electric motor.[28] Once again, BBC Radio 4 had to make do with the pips during this time. The intention is that the clock should run accurately for a further 200 years before major maintenance is again required[29]
17 April 2013: The bells were silenced as a mark of "profound dignity and deep respect" during the funeral of Margaret Thatcher.[30]
August 2015: The clock was discovered to be running 7 seconds fast, and coins were removed from its pendulum to correct the error, which caused it to then run slow. It has since calmed down.[31]