BORIS JOHNSON must stop using high office to fund his lavish lifestyle, Labour said today, after it was revealed that the Prime Minister remains under investigation by the Commons sleaze watchdog over a much-criticised Caribbean getaway. 

Parliamentary Commissioner for Standards Kathryn Stone confirmed for the first time today that she is looking into whether the PM properly declared his £15,000 stay at a luxury Mustique hideaway 16 months ago.

Mr Johnson appears on a list of nine MPs now under investigation by the commissioner published under new Commons rules.