Local elections are pored over by politicians and pundits who try to read the runes and extrapolate how parties and their leaders are faring at a national level. Coming midterm in the general election cycle, they are sometimes considered a way to give the prime minister a kicking.
But opinions on what the results mean should always be treated with a big dose of caution. Labour won the biggest share of the vote in the 2011, 2012, 2013 and 2014…