In 1951 Scotland was a divided nation — not, as now, between unionists and separatists but between Conservatives and Labour. Scotland elected 35 Tory and 35 Labour MPs. But a rot started to set in, a rot that has lasted for six decades and has made it hard for any Conservative leader to win a majority of MPs in the House of Commons.

By 1966 Scotland was electing twice as many Labour MPs as Tory MPs. Even in the 1980s when Mrs Thatcher was winning landslide victories in England she was going backwards in Scotland. By 1997 the very foundations of the Scottish Conservative party were riddled with rot; north of the border became a Tory-free zone. Even now there’s only one Scottish Tory MP.