BORIS JOHNSON was forced to apologise to MPs today for failing to declare more than £52,000 in income.

The Commons standards watchdog had suggested that the former foreign secretary showed an “over-casual attitude” to the rules by repeatedly failing to register payments within the required timetable.

MPs have to register any changes to their financial interests each month, but Mr Johnson’s registrations were late on four separate occasions, involving nine payments.

Kathryn Stone, parliamentary commissioner for standards, said the number of late registrations suggested a “lack of attention to the House’s requirements, rather than inadvertent error.”

But the committee said there were no grounds for supposing Mr Johnson “intended to deceive the House or the general public,” though it criticised his “over-casual attitude” to the rules.

The committee concluded: “We recommend that Mr Johnson should make an apology to the House, on a point of order, for this breach of the rules.”

Mr Johnson offered a “full and unreserved” apology in a 35-second statement in the House of Commons.

The nine late registrations had a total value of £52,722.80, and were largely royalties or for the sale of rights on books already written.

The committee noted that aggravating factors in calling for Mr Johnson to apologise included the size of the sums involved, the number of breaches and that he had been an MP over four parliaments, and had been a senior minister, saying he “could be expected to set an example within the House.”

Mr Johnson has a number of sources of income outside his £77,379 salary as an MP.

Since quitting as foreign secretary he has resumed his column for the Daily Telegraph – for which he earns almost £23,000 a month.

On November 2 he received £94,507 from GoldenTreeAsset Management in New York, with travel and accommodation, for a two-hour speech.