It is a truism that history is written by the victors. As Margaret Thatcher's economic policies were continued after she left office, culminating in economic catastrophe in 2008, it is necessary to throw out the myths peddled about her. The first is that she was popular. The second is that she delivered economic success.

Unlike previous governments, Thatcher's never commanded anything close to a majority in a general election. The Tories' biggest share of the vote under her was less than 44% in 1979, after which her vote fell. The false assertions about her popularity are used to insist that Labour can only succeed by carrying out Tory policies. But this is untrue.

The reason for the parliamentary landslide in 1983 was not Thatcher's popularity – her share of the vote fell to 42% – but the loss of votes to the defectors of the SDP and their alliance with the Liberals. Labour's voters did not defect to the Tories, whose long-term decline continued under Thatcher....