In September 1931, as part of its attempts to deal with the Great Depression, the Government launched cuts to public spending. It was primarily Sir Frederick Field, First Sea Lord, in the committee of Imperial Defence, that led to the abandonment of the ‘ten year rule’. This had been an attempt by the treasury to control defence expenditure. The greatest crisis faced by Field at the Admiralty was the pay crisis that soon followed. 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%.
11 September, Sailors of the Atlantic Fleet arrived at Invergordon, on the Cromarty Firth in Scotland. They 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.
12 September, orders were received from the Admiralty confirming the pay cuts. In the evening, a group of sailors met at a football field on land. They voted to organise a strike and left singing the Red Flag.
13 September, Rear-Admiral Wilfrid Tomkinson, in Temporary Command of the Fleet, received a letter from the Admiralty that stated the reasons for the reduction in pay and the principles on which it had been based. A number of speeches were made criticising the cuts at the canteen ashore. The Officer of the Patrol reported this disturbance and requested reinforcements. Extra patrols were sent and the canteen was closed early. The crews left peacefully, although further speeches were made at the pier. After considering reports about the incident Tomkinson decided not to take disciplinary action over the disturbances. He reported the incident, and his decision, to the Admiralty by telegram.
14 September, 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. Tomkinson was informed that patrols had been dispatched to deal with further disturbances at the canteen and in the open air ashore. These disturbances were characterised as disorderly, and civilians were reportedly spotted amongst the sailors. The Officer of the Patrol was able to address the assembly, but speeches, cheering and singing recommenced after he had finished. The sailors returned to their ships; however many gathered on deck after their return and continued their protests. Tomkinson informed the Admiralty of the protests, stating that the cause seemed to be the disproportionate pay cut of 25% for some ratings.
15 September, reports indicated that there was no trouble in the cruisers, but crews on the battlecruiser Hood and three battleships intended to prevent their ships from sailing in practice manoeuvres; the protests were confined to ratings below leading rate, and did not show any animosity towards officers. In the early hours of 15 September, Tomkinson considered cancelling the exercises. However, after discussions with several flag officers he decided against this, expecting that Repulse would follow orders and this would quell any resistance on other ships. He ordered commanders to investigate complaints in due course and report typical cases that he could use to represent the protests to the Admiralty, and informed the Admiralty that he expected problems sailing in the morning.
On the morning of 15 September, Repulse sailed on time at 06:30. However, sailors on the other four battleships due to sail had already begun to refuse orders. Valiant unmoored and attempted to put to sea with a limited number of men on duty, but was unable to proceed. On Tomkinson's own ship, Hood, striking crewmembers prevented officers and senior ratings from unmooring the ship. Even Royal Marines, expected to enforce discipline and break up any mutiny, joined the strike. Tomkinson suspended the exercises until further notice, cancelled all leave and called for the investigations of complaints to proceed as quickly as possible.
In the afternoon, Tomkinson again informed the Admiralty of the situation and its chief cause, asking for an early decision to be communicated and stating he did not believe it would be possible to restore order, or prevent further deterioration of the situation, until a decision was received. He finally received a reply at 20:00, instructing him to inform sailors that the existing pay rates would remain in force until the end of the month and that the Admiralty expected the men to uphold the traditions of service and carry out their duties. The Admiralty stated that the cut in pay was only 10%, but this ignored the situation for those on the old pay rate. In a second telegram, Tomkinson was instructed to resume exercises as soon as he had completed his investigations into the complaints. Tomkinson believed that this response showed he had failed to communicate the gravity of the situation and replied that it would be impossible to resume exercises in the circumstances. Incitements to stop work were spreading from deck to deck. There were also reports that some of the Petty Officers, who had so far continued to follow orders although they had not attempted to get junior ratings to return to work, were starting to join the strike.
16 September, Tomkinson informed the Fleet that Admiral Colvin had been dispatched to the Admiralty to present sailors' complaints in person, but no decision could reasonably be expected for a day or two; he expected all crews to return to duty.
On the morning of 16 September, Tomkinson received the last of the complaints. He dispatched the Fleet Accountant Officer with these to the Admiralty, and sent extracts by telegram. Having discussed the situation with Rear-Admirals Astley-Rushton (Second Cruiser Squadron, on Dorsetshire) and French (Second Battle Squadron, on Warspite), he reported his belief that the mutiny would worsen unless an immediate concession was made. He suggested junior ratings on the old rate should remain on that rate with a cut of 10%, and marriage allowances should be extended to ratings under the age of 25. He also asked that members of the Admiralty board visit Invergordon to discuss matters in person. Shortly afterwards, he was informed by the Admiralty that the matter was being considered by the Cabinet, and communicated this to the Fleet. Some sailors were threatening to damage machinery and leave ships without permission. In the afternoon, the Admiralty ordered the ships of the Fleet to return to their home ports immediately. Tomkinson directed the ships to proceed in their squadrons as soon as possible, and gave officers and crew with family at Invergordon leave to visit the shore and say their goodbyes. That night, all ships sailed from Invergordon as ordered.
In summarising the mutiny for the Admiralty, Tomkinson reported that the crews had remained respectful to their officers throughout, and that officers had done their best to explain the government's reasons for the cut in pay and that complaints would be taken seriously. He concluded that the mutiny had been caused primarily by the 25% cut for junior ratings who had joined the service before 1925, that there were no grievances besides the pay cut, and his belief that the complaint was well founded. He also believed that any use of force would have made the situation much worse.
The Cabinet accepted Tomkinson's recommendation that ratings on the old rate of pay remain on that rate, with a 10% cut in line with the rest of the service. It was made clear that further acts of insurrection would be severely punished. The Admiralty held Tomkinson accountable for the mutiny, blaming him for failing to punish dissidents after the first protests.
The Invergordon Mutiny caused a panic on the London Stock Exchange and a run on the pound, bringing Britain's economic troubles to a head that forced it off the Gold Standard on September 20, 1931.