The Met is planning to buy three second hand water cannon from German police at an estimated cost of £200,000.
Speaking this morning, Boris Johnson said: "I have concluded there is broad support amongst Londoners for the use of this measure by the police in limited circumstances."
The majority of the 25 Assembly members - including Conservatives - are opposed to water cannon.
More top news
A report by Labour's mayoral candidate, David Lammy, says nine in 10 shoplifting incidents are not reported to police.
Visitors will be able to hop on board 5972 Olton Hall, which weighs 75 tonnes, as part of a new exhibit opening at the attraction in March.
The story of the years preceding Mohammed Emwazi's arrival in Syria is a complex one.