Labour's tax on City deals would be a big vote winner | Larry Elliott

Financial sector is rattled by John McDonnell's support for an FTT that would raise about 7bn a year

A comprehensive tax on financial transactions once seemed like a pipe dream but is now only a few months and a general election away.

When asked at an event last week if he would support a new plan that would raise an estimated 7bn a year for the exchequer, the shadow chancellor, John McDonnell, had a one-word answer: yes. The proposals were unchallengeable, he said.

More churn has meant more short-termism