When I was in Japan recently, critics of Yukio Hatoyama often said that the prime minister was in the habit of making nice-sounding promises that he later found it impossible to keep. Exhibit one was Hatoyama’s pledge to renegotiate the deal covering the US military bases in Okinawa and to move an important marine base off the island completely. Predictably, Hatoyama has now had to back down. But – what the hell – it helped win the election.

The whole episode got me thinking about the British election. If David Cameron becomes prime minister over the weekend, as seems increasingly likely, what pledges can we expect him to break first? Three candidates that spring to mind: Read more