The Home Guard would have struggled to resist an invasion should one have been launched during the first 12 months of its existence. However, by late 1941, the force was better armed and trained, and more capable of helping the regular army repel an invasion.
The initial phase of Operation Sealion was to land 11 divisions along the south coast of England between Dover and Weymouth, assisted by two divisions of airborne troops dropped on the Downs above Brighton and Folkestone – similar in many respects to the Allies’ invasion plans for Normandy four years later, but with considerably less preparation and poorer equipment.
The soldiers were to be towed across the channel in a motley collection of barges, which just months earlier had been ferrying freight up and down the river Rhine. They were of shallow draft and easily swamped in heavy seas. Should the Germans have successfully gained a foothold, the Home Guard would certainly have caused problems, but in my view all effective resistance would have been very short term.
Between July and December 1940, thousands of pillboxes were constructed around Britain’s coastline and at strategic points further inland – they would have certainly made a difference, but I feel it would have been too little too late. If the Germans had successfully occupied Britain following a 1940 invasion, I’m certain that resistance groups, organised along similar lines to those seen in other parts of occupied Europe, would have sprung up. They would of course have been totally independent of British government control.
Following Germany’s unsuccessful invasion of Russian in June 1941, the threat of an invasion of Britain was no longer a realistic prospect. However, had more resources been pumped into its V-1 and V-2 rocket programmes, then I feel the Allies may have been forced to accept German hegemony on the continent in exchange for a ceasefire.
It should also be remembered that German scientists were working on the development of nuclear weapons, and had they managed to couple a nuclear warhead to a V-2 rocket, then the outcome may have been very different!