Sir Keir Starmer is under investigation over failures to register gifts from football teams and book royalties worth thousands of pounds on time.

The Labour leader’s visit to watch his Arsenal team face Watford at Vicarage Road in March is among the incidents being probed by the Parliamentary Standards Commissioner.

Sir Kier says he was “absolutely confident” he had not broken the MPs’ code of conduct.

But he apologised to watchdog Kathryn Stone “for the fact that administrative errors in his office have led to a small number of late declarations”, according to his spokesman.

Ms Stone launched an investigation last Wednesday into whether the opposition party leader had broken the rules by failing to register financial interests within 28 days of receipt.

Watford Observer: Labour leader Sir Keir Starmer. Credit: PALabour leader Sir Keir Starmer. Credit: PA

A Labour source confirmed the investigation relates to delayed declarations of hospitality at football matches, book royalties and donations to staff from the Just Eat food delivery firm.

This includes four tickets Sir Keir received, worth a total of £1,416, for the Watford vs Arsenal Premier League fixture at Vicarage Road on March 6. The gift was registered on May 6.

Sir Keir’s visit to a director’s box, worth £720, for Arsenal’s game at Crystal Palace on April 4 is also being investigated. The gift was not registered until May 5.

Watford Observer: Watford faced Arsenal in the Premier League in March. Pictured are the players from both teams showing their support for Ukraine ahead of the game. Credit: PAWatford faced Arsenal in the Premier League in March. Pictured are the players from both teams showing their support for Ukraine ahead of the game. Credit: PA

The £18,450 the Labour politician received from publisher HarperCollins in April for a book he is writing appears to have been declared a day late, while royalties for two legal books published before the lawyer became an MP were also delayed. These are also being investigated.

In 2019, Prime Minister Boris Johnson was found to have breached standards rules by failing to declare within the time limit a 20 per cent share of the ownership of a property in Somerset.

A report four months earlier by Ms Stone also found Mr Johnson was late registering financial interests on four previous occasions involving nine separate payments.

The MPs’ code states: “Members shall fulfil conscientiously the requirements of the House in respect of the registration of interests in the Register of Members’ Financial Interests.

“They shall always be open and frank in drawing attention to any relevant interest in any proceeding of the House or its committees, and in any communications with ministers, members, public officials or public office holders.”