British police will be "looking into" a video in which Prime Minister Rishi Sunak can be seen riding in a car without a seatbelt - an "error of judgment" for which he has apologised, according to Downing Street.

In Thursday's video, produced for distribution on Sunak's social media channels, the seatbelt-less Conservative leader speaks from the back seat of a moving car about his policies for boosting growth during a trip to Lancashire in England's north.

Failing to wear a seatbelt is punishable by a fine of up to $619 (500 pounds).

A Lancashire police spokesperson said authorities were "aware of the matter and we will be looking into it". 

'An error of judgment'

A spokesperson for Downing Street said that Sunak "fully accepts this was a mistake and apologises".

"The prime minister believes everyone should wear a seatbelt," the spokesperson added. 

"It was an error of judgment. He removed it for a short period of time to film a clip, which you've seen, but he accepts that was a mistake."

Sunak's transportation habits had already been a talking point in the United Kingdom, with his political rivals taking aim at his use of a jet to make multiple short flights in recent days.

Deputy Labour leader Angela Rayner said: "Rishi Sunak's expensive private jet habit is costing the environment and the taxpayer dear."

A spokesperson, however, defended the decision, saying Sunak used "different modes of transport depending on what's... the best use of his time to enable him to get around the entire UK".

READ MORE: Rishi Sunak vows 'stability and unity' as UK's next prime minister