A senior minister has said Boris Johnson did pay for the refurbishment of his official Downing Street flat out of his own pocket, but was unable to say where he got the money.International Trade Secretary Liz Truss said she had been assured the rules for ministers had been fully complied with and that the details would be declared publicly.However, Labour called on the Electoral Commission to mount a full investigation after Mr Johnson’s former top adviser, Dominic Cummings, claimed he tried to get Tory donors secretly to fund the work.Deputy leader Angela Rayner said there is a “real stench” around the Government and called on Mr Johnson to go to Parliament on Monday to explain what happened.