UK Home Secretary Suella Braverman on Monday denied any impropriety over the handling of a speeding ticket that has again put her at the centre of controversy about alleged rule-breaking.

Rishi Sunak promised to restore integrity to government when he became prime minister last year, after the turbulent premierships of Boris Johnson and Liz Truss.

But Braverman – a Brexit hardliner criticised for her outspoken rhetoric on immigration – is now facing calls for a potentially career-ending ethics inquiry.

The interior minister in charge of law enforcement asked her officials to set up a one-to-one driving awareness course, instead of taking penalty points on her licence, according to newspaper reports on Sunday.

That has led to opposition claims that she may have breached the ministerial code of conduct by requesting non-political civil servants to help deal with a private matter.

Braverman, who resigned under Truss for using her personal email to send an official document to a colleague, downplayed the row in comments to media and to parliament.

"Last summer, I was speeding. I regret that," she told the House of Commons, referring back to when she was attorney general before becoming home secretary under Truss in September.

"I paid the fine and I accepted the points, and at no point did I seek to evade the sanction," Braverman insisted.

But she thrice refused to answer when pressed by opposition parties about what she had directed civil servants to do on her behalf.

"Time and again she tries to think that she's above the normal rules," senior Labour MP Yvette Cooper charged, while accusing Sunak of being "weak".

The prime minister was asked about the newspaper reports while at the G7 leaders' summit in Japan and said he did not know the "full details" of the case.

Downing Street later said that "of course" he had full confidence in Braverman. (AFP)