Causes
In September 1931, as part of its attempts to deal with the Great Depression, the new National Government launched cuts to public spending. The recommended cuts in spending on the navy were translated into a 10% pay cut (matching 10% cuts across the board for public sector workers) for officers and senior ratings, and for all junior ratings on the "new rate" of pay (introduced for new entrants from 1925). A 10% cut would cause great hardship to the already poorly-paid ratings. Those ratings below Petty Officer who had joined before 1925 would also have their pay reduced to the new rate; this amounted to a cut of 25%. On top of this, many Labour party supporters shared the sense of betrayal felt in the labour movement at Ramsay MacDonald's split with the Labour Party and his formation of a new government with the Conservatives.
Sailors of the Atlantic Fleet, arriving at Invergordon, on the Cromarty Firth in Scotland, in the afternoon of Friday 11 September, learned about the cuts from newspaper reports; some reports implied that a 25% cut would be imposed on all ratings. The shock of this news had a palpable effect. On 12 September, orders were received from the Admiralty confirming the pay cuts. On the evening of 13 September, by which time sailors had already started agitating, Rear-Admiral Wilfred Tomkinson (in temporary command of the fleet while Admiral Sir Michael Hodges was in hospital) received a letter from the Admiralty dated 10 September. This letter stated the reasons for the reduction in pay and the principles on which it had been based. The following morning, Tomkinson ordered the commanders of all ships present to read sections of the Admiralty letter out to their officers and crew. However, several ships had not received copies of the letter and some were unable to pass the information on to their companies until the next day. By that time, the mood for a strike had taken hold in many crews.
Read more about this topic: Invergordon Mutiny