On the political map of Britain, London has long been an island of Labour red in a South East sea of Conservative blue. London has traditionally been Labour at its centre and Tory on its fringes.
The mayoral elections underlined that pattern, with some significant additional wins for Sadiq Khan in previously Conservative ground of Merton and Wandsworth, and Ealing and Hillingdon.
The other significant change is the increase in Labour support in the central areas that have seen the fastest population rise. The constituency of City and East is a good example. It contains Tower Hamlets and Newham, the boroughs forecast to grow fastest in the coming decade. In these areas Sadiq Khan achieved 60% of first preference votes and the greater population and high turnout delivered nearly 20,000 more Labour voters than in 2012.
It was a similar story in the North East constituency which covers Islington, Hackney and Waltham Forest. Khan again achieved a 60% share and added 36,000 votes on 2012.
Zac Goldsmiths best performance was in the Bexley and Bromley. He out-polled Sadiq Khan here by two votes to one, but his number of votes was down on Boris Johnson’s haul in 2012 and his share was 51% compared to 62% for the Conservatives four years ago.
In Havering and Redbridge, and his home South West constituency, which includes Richmond, Hounslow and Kingston, he increased the number of votes, but not in Croydon and Sutton or the West Central constituency covering Westminster, Kensington and Chelsea, and Hammersmith and Fulham.
In all 5 areas won by the Goldsmith, the Conservative share of the vote was down on 2012. This might be attributed to the success of Boris Johnson as a larger-than-life character who worked across traditional party loyalties. Many, including leading Conservatives, have criticised the Goldsmith campaign, with its attacks on Khan, as negative and off putting for voters.
But the voting patterns indicate something more than personality politics and suggest an underlying sentiment. A breakdown of all first preference votes into blocks representing broad party positions shows that parties of the left out-performed the parties of the right.
And the second preference votes also tell a story. In the final run off Khan and Goldsmith were awarded the second preference votes of all the other candidates. Khan won convincingly here. But we can also see from the data how the second preferences of Khan and Goldsmith voters would have been deployed if either had not made the final round. A quarter of Goldsmith voters marked Khan as their second preference. Only 14% of Khan voters put a second cross next to Goldsmith. The main beneficiary of second votes were the Greens, who sit on the left.
After two terms of a Tory mayor the capital has a Labour politician as leader again. The city population is forecast to be over 9 million by the time he is up for re-election. The evidence from this election is that a growing number of people is central London is good news for Labour and Sadiq Khan.