The first fines have been issued to people in government for breaking COVID rules at the height of lockdown.
Officials are understood to have received fines thought to be in connection with an event in the Cabinet Office on 18 June 2020.
The fines, worth £50, have been sent to individuals by email. The names of those involved have not been disclosed.
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The event in June 2020 is understood to have been a leaving party for a Number 10 official and was held in the Cabinet Office building at 70 Whitehall.
The decision to issue fines in connection with one of the lower profile events is significant.
Sky News understands that the Metropolitan Police investigation has been slowed down by the need to consult the Crown Prosecution Service.
A CPS lawyer would be needed if the recipient of a fine decided to fight and take the issue to a Magistrates court.
The CPS can ask the police to do more work, or direct them to collect more evidence until it is satisfied it could prosecute a case.
Sky News understands that the Metropolitan Police did not fully consult the CPS at the start of the investigation.
The CPS could have questions about the unusual questionnaires used to extract more information from those in government.
Any decision by a senior political figure to challenge a fine would be a huge moment for the Metropolitan Police.
Downing Street is refusing to say that the issuing of fines represents proof of criminality – which has been taken in parts of Whitehall as a sign Boris Johnson would appeal if he was personally fined.
Two Cabinet ministers – justice secretary Dominic Raab and international trade secretary Anne-Marie Trevelyan – have concceded that the penalties meant laws were broken.