A confidence ballot in Boris Johnson may or may not be triggered this week. While we wait to find out, here is a potted history of Conservative leadership elections
- Nine Conservative MPs have been returned as Party leader since elections have been introduced – Edward Heath in 1965, Margaret Thatcher in 1975, John Major in 1990 and 1995, William Hague in 1997, Iain Duncan Smith in 2001, Michael Howard in 2003, David Cameron in 2005, Theresa May in 2016 and Boris Johnson in 2019.
- Five of these nine were elected by MPs only (Heath, Thatcher, Major, Hague and Howard) and four by MPs and party members (Duncan Smith, Cameron, May, Johnson).
- Six of the nine became Prime Minister: Heath, Thatcher, Major, Cameron, May and Johnson.
- Three of the nine became Prime Minister after being elected Conservative leader (Major, May, Johnson). Three of the nine became Prime Minister having formed a government after a general election (Heath in 1970, Thatcher in 1979, Cameron in 2010).
- One of the nine was elected unopposed – Michael Howard.
- Two were backbenchers when elected – Howard and Johnson.
- Four were subject to leadership challenges: Heath, Thatcher (twice), Duncan Smith and May.
- Three of these took place before the rules governing challenges were changed in 1998 (Heath and Thatcher, twice) and two after (Duncan Smith and May).
- Two were Leader of the Opposition when challenged: Heath and Duncan Smith. Both lost. Heath was challenged by Thatcher in 1975. Duncan Smith contested a ballot of Conservative MPs in 2003 that had been triggered by the required percentage of Tory MPs.
- Two were Prime Minister when challenged: Thatcher and May. Both won (Thatcher twice). Thatcher was challenged by Anthony Meyer in 1989 and by Michael Heseltine in 1990. May contested a ballot of Conservative MPs that had been triggered by the required percentage of Conservative MPs.
- Thatcher resigned shortly after winning the first ballot of the 1990 contest; May resigned in June 2019 having won a ballot of Conservative MPs in December 2018.
- John Major resigned as Conservative leader in 1995, stood for re-election, and was returned by Tory MPs.
The only point I would stress is that no Conservative leader challenged when Prime Minister has either a) lost a confidence ballot and b) survived winning one by even a year (the Meyer challenge to Thatcher took place in December 1989, the Heseltine one in November 1990).