The officers are protesting against proposed changes to their pay and conditions.
Some 20,000 officers from all 43 forces across England and Wales are thought to be taking part in the first police march in the capital for more than four years.
More top news
Public services union Unison says it will nominate Jeremy Corbyn in the Labour Party leadership contest.
Google search now shows you when businesses and attractions are busiest.
The planning application said the museum would be dedicated to celebrating the achievements of East End women. Residents are very angry.