LONDON (Reuters) - British police fined Prime Minister Rishi Sunak on Friday for riding in a car without a seatbelt while filming a social media clip, a potential embarrassing blow as he tries to revive the fate of his party.

Sunak was filming a clip from the back seat of his car while traveling in the north of England without wearing a seatbelt, but he apologized Thursday for what he described as a "short-term error of judgment" after the clip spread on social media.

A spokesman for Sunak's Downing Street office said - in a statement - "The prime minister fully accepts that this was a mistake and has apologised. He will of course abide by the fine."

Lancashire Police in northern England confirmed that they had issued a fine notice for a 42-year-old man from London.

The fine represents a new challenge for Sunak, whose Conservative Party is far behind the opposition Labor Party in opinion polls, before the elections scheduled for January 2025 at the latest.

This is the second punishment that Sunak receives from the police, after it was discovered last year that he had violated the rules of closing Covid-19 alongside then-Prime Minister Boris Johnson, and Sunak also became the second prime minister - after Johnson - to be fined in this way.