Rishi Sunak’s spokesperson said the prime minister did not agree with comments made by Gen Sir Patrick Sanders in a speech on Wednesday, and was forced to insist there would be no return to national service, which was abolished in 1960.

“Hypothetical scenarios” involving possible future wars was “not helpful”, the No 10 spokesperson added, as the row opened up a rift between the Conservatives and the military at a time when cuts mean the army is at its smallest for more than 300 years.