The Brady amendment is part of the developing story of a clash between leaders and backbenchers over Party management, culture and MPs’ status.
Patrick Bishop’s biography of Airey Neave, who in 1975 showed how to run a successful leadership campaign.
Behind his languid exterior lay a man of unusual principle, to whom all Conservatives have cause to be grateful.
Many eyes are on the Mayor of London, but more should be on the Home Secretary – as the only holder of a great office of state who may yet back Leave.