The 2001 general election, when I unsuccessfully led the Conservative Party into battle against Tony Blair, now seems as if it belonged to a different era. The techniques used and policies presented would have been more familiar in elections of half a century earlier, in the 1950s, than in this utterly different contest just 18 years later.

Much of the rapid change in how elections are fought is the result of new technology: in 2001 we were still spending our campaign resources on huge advertising hoardings seen by everyone, rather than the targeted social media operations today.

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But most striking is the consensus within which we all operated at that time. Labour under Blair set out to portray itself as a party safe for big-hearted Tories, conspicuously abandoning socialism. Whenever we Conservatives had a good idea, he would simply steal it. I wanted taxes to be a tiny bit lower than he did. He set spending slightly higher than I would have done. I was against the euro, but he wasn’t joining it anyway. And both of us wanted to prevent Gordon Brown becoming prime minister. We agreed on a lot. Voters knew in 2001 that they were not at a major inflection point. Neither main party was going to raise income taxes; both were committed to a close alliance with the US president; nationalisation was unthinkable.