Boris Johnson's old post has been digged out about his racism post

Critics are urging Mr Johnson to explain whether he still holds the views expounded in the 2002 piece, where he argued that Africans would not have grown the right crops for export without British direction.

“The continent may be a blot, but it is not a blot upon our conscience,” he wrote. “The problem is not that we were once in charge, but that we are not in charge any more.”

The prime minister this week argued for the retention of controversial statues of slavers and British colonialists in UK cities, which he said should stay up because they “teach us about our past with all its faults”.

But the article, written while Mr Johnson was editor of The Spectator magazine, reveals that the prime minister in fact has held an active admiration for Britain’s colonial activities on the continent.

“Consider Uganda, pearl of Africa, as an example of the British record. Are we guilty of slavery? Pshaw. It was one of the first duties of Frederick Lugard, who colonised Buganda in the 1890s, to take on and defeat the Arab slavers,” Mr Johnson says in the piece.

“And don’t swallow any of that nonsense about how we planted the ‘wrong crops’. Uganda teems, sprouts, bursts with vegetation. You will find fruits rare and strange, like the jackfruit, hanging bigger than your head and covered with green tetrahedral nodules. Though delicately perfumed, it is, alas, more or less disgusting, and not even Waitrose is pretentious enough to stock it.”

He continues: “So the British planted coffee and cotton and tobacco, and they were broadly right. It is true that coffee prices are currently low; but that is the fault of the Vietnamese, who are shamelessly undercutting the market, and not of the planters of 100 years ago.

“If left to their own devices, the natives would rely on nothing but the instant carbohydrate gratification of the plantain … the colonists correctly saw that the export market was limited.”

Suggesting that one way to boost the economy of African countries would be for British tourists to holiday in them, Mr Johnson wrote: “The best fate for Africa would be if the old colonial powers, or their citizens, scrambled once again in her direction; on the understanding that this time they will not be asked to feel guilty