Winston Churchill was urged to invade Ireland by Northern Ireland Prime Minister Lord Craigavon at the height of the Second World War. Craigavon claimed then Irish leader Eamon De Valera had fallen under Nazi influence and had to be replaced.

According to a Sunday Times report, Craigavon wrote to Churchill in 1940 to ask that Ireland be invaded by using Scottish troops and a military governor installed in Dublin in order to secure the valuable naval bases along the Irish coastline

“To meet the susceptibilities of the south the British forces might best be composed chiefly of Scottish and Welsh divisions,” he wrote in a memorandum to Churchill.

“A military governor should be then be appointed for the whole of Ireland with his HQ in Dublin.”

Craigavon also said distributing propaganda leaflets in Gaelic and English should be used to persuade the Irish that the Celtic regiments were there to defend them.

Churchill did not move at that time but later prepared detailed plans for an invasion of southern Ireland.

Field Marshal Montgomery stated in his memoirs: “I was told to prepare plans for the seizure of Cork and Queenstown in southern Ireland so the harbors could be used as naval bases.”

The previously classified files, are published in a new book, "Britain, Ireland and the Second World War," by the Scottish historian Ian S Wood.

“British forces could have taken control with very little difficulty, but it would have an absolute gift to the IRA who would have launched waves after wave of guerrilla attacks,” he said. “Occupying Eire would have been an extremely messy and costly undertaking.”

Dr. Eamon Phoenix, a political historian at Queen’s University, Belfast, stated that attempting to “camouflage” a British invasion by using Scottish or Welsh troops would have backfired.

“Many of the Black and Tans, the British auxiliaries sent to suppress Irish independence, were Scots and they had an appalling reputation,” he said.

Although Ireland stayed neutral throughout the war, De Valera incensed London by offering his condolences to the German ambassador in Dublin on the death of Hitler.