The “Partygate” affair surrounding British Prime Minister Boris Johnson has reached another symbolic climax.

According to media reports, the Prime Minister has become the first British Prime Minister to be questioned by the police under caution after submitting the questionnaire to the London police on time.

The broadcaster ITV published a leaked questionnaire on Tuesday evening, which Johnson and dozens of others allegedly involved in lockdown parties in Downing Street had to fill out.

From this it follows that the answers are considered to be surveys "under caution".

The suspects were asked if they attended the allegedly unlawful parties and why and how they interacted with others present.

Respondents can also indicate when they think there was a “lawful exception” or “just excuse”.

The outcome of the police investigation could be crucial to Johnson's political future.

Some Conservative MPs have already called for his resignation, while others want to await the investigation.

If at least 54 Tory MPs vote no confidence in Johnson, there would be a vote of no confidence.

Johnson is said to have tolerated and attended some of Downing Street parties during lockdown.

He himself denies having broken his own rules.

The deputy leader of the opposition Labor party, Angela Rayner, described it as a "national disgrace" that Johnson was now probably the first prime minister in British history to be questioned by the police under threat of punishment.

"How on earth can he go on and claim to uphold law and order?" she added.