Police are investigating 12 parties in Downing Street and Whitehall, including a birthday gathering for Boris Johnson, according to Sue Gray's report.
The top civil servant revealed she was looking at 16 events in her partygate probe - and 12 of those are being examined by the Metropolitan Police.
Ms Gray said it was "not possible at present to provide a meaningful report" setting out all she discovered, due to the ongoing police investigation.
