There are 10 seats where the Green vote is bigger than the Tory majority.
Obviously it is not clear that every Green voter would have voted
Labour, but some may have done if they had known it could have elected a
Labour, instead of Tory MP.
With Sinn Fein not taking their 4 seats in Westminster, 324 seats are
required for a working majority. The Tories got 331. If 8 out of 10 of
the seats above were won by Labour the Tories would not have a majority