City Hall: Elections in context

Noah Vickers, Local Democracy Reporter, takes a look back at the data from previous contests

As votes are counted for the London mayoral election, the Local Democracy Reporting Service has taken a look back at the data from previous contests to see how Sadiq Khan and Susan Hall’s performances might measure up.

Figures released on Friday showed that turnout was down in all seven London Assembly constituencies in which Labour’s Khan polled more first preference votes than his Tory rival Shaun Bailey in 2021. Turnout had meanwhile risen in some of the capital’s most Conservative-dominated areas.

This has led to suggestions that the race will be far closer than the lead of 10 or more percentage points which the polls had suggested Khan had over Conservative candidate Hall.

But whoever wins, what will their victory look like in the context of the mayoralty’s 24-year history?

Which London mayors achieved the best and worst results?

The best ever result for a winning candidate in terms of vote-share was achieved by Khan in 2016, when he secured his first term as mayor with 44.2 per cent of ‘first preference’ votes, under the old ‘supplementary vote’ system.

For this year’s City Hall election and others going forward, the voting system has been changed to ‘first past the post’, meaning that voters are no longer able to choose a first and second preference for mayor. The winning candidate now simply has to receive more votes than any other.

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The lowest win, by vote-share, was that of Labour’s Ken Livingstone when he won re-election in 2004, with 37 per cent of first preferences. This was down from the 39 per cent he received when running as an independent in 2000.

In that earlier contest – the capital’s first mayoral election – Livingstone achieved the largest margin of victory by a London mayor over their nearest opponent, defeating Tory candidate Steven Norris by 11.9 percentage points.

By contrast, the narrowest winning margin was held by Tory mayor Boris Johnson when he secured a second term in 2012 with just 3.7 percentage points over Livingstone.

If the winner of 2024’s contest claims victory with less than 37 per cent of the vote therefore, or wins by a narrower margin than 3.7 points over their rival, it could be argued that they have won the smallest mandate of any London mayor.

Which ‘runners up’ for mayor have achieved the worst and best results?

The poorest showing for a runner up was Tory candidate Steven Norris’s result in 2000’s contest, when he received 27.1 per cent of first preferences.

The best ‘second place’ result in the mayoralty’s history was achieved by Labour’s Livingstone in 2012, the year that Johnson was re-elected. In that year, Livingstone took 40.3 per cent of first preferences – a slightly higher share than even Khan received when he was re-elected as mayor in 2021.

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