Early arrivers have been making their way to the Patron's Lunch on The Mall, the final public celebration of the Queen's 90th birthday.
The weather has been wet and miserable, but spirits appear to be high.
Rows of plastic chairs and tables awaited the lucky ticket holders, who each paid £150 to attend.
Organisers apologised for the delays to get in, due to security checks.
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The finale of the Queen's official birthday is The Patron's Lunch street party.
It seems like just yesterday it was the Queen's birthday and already she is celebrating again. But why does the monarch get two?
The celebrations, which begin on Friday and finish on Sunday, include a thanksgiving service at St Paul's and a party on The Mall.