Hopkinson considered his warnings had been amply justified when the Second World War broke out. He re-enlisted at age 60, this time in the Royal Navy on the declaration of war, serving from 1939 to 1942. During breaks in his service he voted against Chamberlain after the Norway debate of 1940, and supported Churchill's policy of 'total war', but opposed the use of secret sessions of the House of Commons to suppress public criticism of the performance of Ministers. In 1942 a corrupted report of a speech of his was printed in the "This England" column of the "New Statesman" in which he was supposed to have declared himself an autocrat. Hopkinson sued for libel, describing the statement as a travesty. The "New Statesman" eventually agreed to pay 50 guineas to the RAF Benevolent Fund in damages, and Hopkinson's costs. The same erroneous report also appeared in "Reynolds News" and Hopkinson won £500 damages from them.