Nationally the share of the vote looked like this:

Tories 44%
Labour 24%

In London, with a socialist candidate the share of the vote looked like this:

Johnson 42%
Livingstone 36%

Grimmer mentions their candidate, Janet Oosthuysen, falling short of ousting the Lib Dems by 53 votes, they campaigned on a slogan of "Vote Labour - Get a Socialist".

I think there is a message here for the Labour Party and somewhere in it is the 'S' word.