Green leader Zack Polanski runs for MP. Most such races drew over 40% turnout.

Zack Polanski, the Green leader, will stand in the Holborn and St Pancras byelection on 8 October, the sixth party leader since 2012 to do so.

4 of 6Four of the last six byelections with a party leader on the ballot cleared 40% turnout, and none of them passed 51%.

Is turnout above 40% in Holborn and St Pancras on 8 October?

History4 of 6Hunch48%

Labour defends Keir Starmer's seat. Few governments kept such seats this early.

Governing parties held two of the last eight seats they defended at a byelection in the first three years of a parliament.

History25%Hunch65%

17 of 19 MPs who resigned to re-fight their seat since 1982 won it back; both losers faced a major-party machine.

History89%Hunch89%

Labour has won every Greater Manchester mayoral contest, never below 63%. Every one of those wins was Burnham's.

History3 of 3