Police in London attached a letter to their questionnaire outlining its legal weight, which was emailed to more than 50 people in No 10, including the Conservative leader.
Under the Police and Crime Evidence Act 1984, a caution must be administered where a person is suspected of committing a criminal offence and is to be questioned about it. This is to ensure their answers – or silence – will be admissible in proceedings.
Mr Johnson is understood to be the first prime minister in Britain to be subject to that level of police questioning. Being sent a questionnaire under caution carries the same weight as being interviewed by police under caution.
The questioning forms part of the Metropolitan Police’s Operation Hillman investigation into about a dozen parties suspected to have been held in Downing Street while Covid-19 restrictions were in place.
“It is our intention to establish the details of the alleged breach and provide you with the opportunity to co-operate with police in the form of a written statement under caution,” the letter read, according to a leaked copy seen by ITV News.
It makes clear the recipient has three options:
· Do not answer the questions
· Provide written answers to the questions listed on the form
· Submit a prepared statement in your own words
Each recipient was asked to give a “lawful exception” or “reasonable excuse” for any party they attended. It states at the outset suspects have an opportunity to provide “a written statement under caution”.
Around a dozen questions follow, including:
· “Did you participate in a gathering on a specific date?"
· “What was the purpose of your participation in that gathering?”
· “Did you interact with, or undertake any activity with, other persons present at the gathering? If yes, please provide details”
The prime minister has already admitted attending multiple gatherings but insists they were held for work purposes.
He has already returned his questionnaire to Scotland Yard.
Downing Street said this month he would not receive personal legal advice from government lawyers on the matter.
Criminal law barrister Andrew Keogh said the questionnaire "suggests that this is not a thorough investigation" and said the questions put forward are "as basic as you can possibly imagine them to be".
The Met Police had faced criticism over a reluctance to launch a probe into the parties, before announcing in January a criminal investigation would take place.