In the condolence book David Cameron wrote:
This was a deeply shameful event in British history, one that Winston Churchill rightly described at the time as 'monstrous'.
We must never forget what happened here, and in remembering we must ensure that the United Kingdom stands up for the right of peaceful protest around the world.
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Rain will spread southeastwards through N. Ireland, Wales and England overnight.
The woman used her daughter's own Facebook page to live-stream the attack after the teenager posted provocative pictures online.
A senior employee at the organisation reportedly derided the three-year-old royal for being 'royal, rich' and "advantaged'.