Boris Johnson breached Commons rules by not declaring a financial interest in time, a committee of MPs has found.
The Committee on Standards said the former foreign secretary had failed to register a share of a Somerset property within 28 days of buying it.
The committee accepted he had not intended to conceal his interest and had apologised.
But it added that the Conservative MP had shown an “an over-casual attitude” to parliamentary rules.
‘Pattern of behaviour’
The reprimand follows a similar finding in December, when Mr Johnson was ordered to apologise over the late declaration of £52,000 in book royalty payments.
In its latest report, the committee said the failure to declare the property interest in time revealed a “pattern of behaviour” regarding respect for rules on declarations.
It recommended Mr Johnson, MP for Uxbridge and South Ruislip, receives a briefing from the Registrar of Members’ Financial Interests on his obligations.
It added that it may call for “more serious” sanctions if he is found guilty of another breach in future.
According to the committee’s report, Mr Johnson acquired the interest in the property in January 2018 but did not register it for another year.
He told the Parliamentary Commissioner for Standards he had not thought it necessary to register the property, as he had initially misinterpreted the rules relating to the threshold above which an interest has to be declared.