It is odd to think of David Cameron as the most electorally unsuccessful Tory prime minister in history.
So writes Spectator editor Fraser Nelson in his Observer review of Michael Ashcroft's 'Minority Report', Nick Boles' Coalitionist tract and the Cowley/Kavanagh study of the 2010 General Election.
The claim strikes me as somewhat exaggerated. Cameroon loyalists might find it helpful to have the evidence as to why David Cameron can not quite claim his party's wooden spoon, though he might stake a reasonable claim to it if we restrict the search to the period after the Great War (on which the House of Commons Library has a useful summary of the post-1918 trends. (PDF).
But I think Arthur Balfour must surely claim the prize for the least successful Tory prime minister ever, succeeding his more electorally successful uncle Lord Salisbury mid-term in 1902 before splitting the government and party over tariff reform, and resigning as PM at the end of 1905 (in the hope of splitting his Liberal opponents too) before being trounced in the Liberal landslide of 1906.
In terms of vote share, the Tory performance in 2010 was their fifth worst in the 25 general elections since (near) universal suffrage in 1918.
Cameron got his 36% from opposition. Of the four worse results, only John Major's 31% in 1997 was achieved by a Prime Minister, though Major did previously achieve a majority in very difficult circumstances in 1992, while Cameron failed to do so in extremely auspicious context in 2010. Cameron's supporters might claim that he would need to perform very badly now to be ranked below Major on the electoral record, but he would also rank behind on election victories if he can not win a future majority.
Ted Heath had been out of office only six months when achieving a very similar share (35.7%) in the second 1974 election to that which Cameron achieved this Spring. Heath did win a surprise majority victory in 1970 against a Labour government with a considerably larger majority than the government held in 2010.
The two least successful Tory Prime Ministers of the 20th century - in terms of their political failure in their own terms - do not figure here as competitors for the electoral wooden spoon with David Cameron. Anthony Eden won a snap landslide in 1955, before his short premiership collapsed over Suez, and Macmillan was able to turn that disaster into a third election victory.
And Neville Chamberlain is the only 20th century Prime Minister who neither won nor lost a general election, succeeding in 1937 and leaving after the collapse of his policy in 1940, without ever troubling the electorate, though he might bear some responsibility for the Tory landslide defeat in 1945. (He could have won a big victory had he heeded calls to cash in on his post-Munich popularity with a snap election in 1938, but his party may be glad he did not.
[* UPDATE: This post should also have mentioned Sir Alec Douglas-Home, narrowly defeated by Harold Wilson in his only General Election in 1964, winning 303 seats out of only 630 and with 43.3% of the vote).
To date, David Cameron is the only other post-1918 Tory PM to have not won himself a Commons majority [*]. But he has time yet to take himself out of the relegation zone.