Britain's Edward VIII was secretly bugged shortly before his abdication as ministers worried about the potential impact of him standing down, documents newly released by the National Archives reveal.
Home Secretary Sir John Simon made the decision that General Post Office (GPO) officials should listen in on the king's phone calls as the crisis over Edward's relationship with American divorcee Wallis Simpson came to a head in December 1936, the papers show.
Previously secret Cabinet Office records show that the Home Office issued the instruction to monitor calls from Buckingham Palace or Edward's home in Fort Belvedere in Windsor Great Park to France, where Simpson was staying with friends.
The previous month the new king, who had yet to be crowned formally, had informed Prime Minister Stanley Baldwin that he intended to marry Simpson, provoking a constitutional crisis.
Baldwin felt the marriage could not be allowed if Edward was to remain on the throne, as at that time the Church of England refused to remarry divorcees while their former spouse was still living.
Documents at the Kew-based National Archives contain a note from the Home Office to the head of the GPO dated December 5, 1936 and marked "Most Secret".
"The Home Secretary asks me to confirm the information conveyed to you orally, with his authority by, by Sir Horace Wilson that you will arrange for the interception of telephone communications between Fort Belvedere and Buckingham Palace on the one hand and the Continent of Europe on the other," it said.
Edward signed the abdication papers five days later after reigning for 326 days.
Another newly-released document is a government instruction to the postmaster general to stop two telegrams on December 6 which were being sent to newspapers in South Africa,"both of which contain statements that the King has abdicated."
Home Secretary Simon summoned the journalist who sent them four days before Edward actually did abdicate, Neil Forbes of the Cape Times, for a dressing down.
Simon told Forbes there was "no truth" in his report and said that if the news had reached South Africa and then been telegraphed back to Britain, the reactions might have been "of a most serious character".
"I reminded him that in 1815 a false rumour that we had lost the Battle of Waterloo produced a financial crisis and ruined many people," the home secretary wrote.