Dad's Army - How useful would the Home Guard have been?

If you're from the UK, you've almost certainly heard of the Home Guard, or "Dad's Army" as it was often called. If you're not from the UK, the Home Guard was a volunteer force set up in May 1940 to bolster defence against German invasion, recruiting people too old, too young or otherwise exempt from being called up to the regular army. The result was basically a force of mostly old men, many of whom had served in the First World War, and a fair few in the earlier Boer Wars and even in African campaigns, like the Sudan. The initial equipment situation was pretty poor, with many having to wear a simple armband rather than an actual uniform, and many equipped with surplus WW1 rifles, Canadian and American imports, civilian shotguns, rifles and pistol, improvised weapons and museum pieces (and there's also the whole Croft's Pikes debacle*). Manpower was no issue though. In the first seven days of the initiative being announced in May 1940, 250,000 men signed up. By July 1,500,000 had joined. However, by 1942 the Home Guard was actually pretty well equipped; with the introduction of the Sten Gun, they could be issued with more modern No.4 rifles. Lewis guns and Bren guns were issued, as were the American Thompson SMGs and BARs. Many units had basic mortars, and some were even issued armoured cars. Training began to improve with time as well, as men of as old as 70 years of age were taught how to deal with tanks and enemy paratroopers (there's that old joke that they were told Germans might dress as nuns to avoid detection). Notable members included George Orwell and C S Lewis.

Anyway, my point is, how effective would they have been? After all, how much use would a poorly equipped, if spirited, band of boys and old men have been against a German Blitzkrieg across the countryside of Southern England? Don't get bogged down in how the Germans got there in the first place, I know they probably couldn't, just assume they did. I'd say it depends a lot on when the Germans invaded. If it was immediately after the Fall of France, in 1940, it'd probably be a total wipeout. 739,000 of the Home Guard were still without weapons in late 1940, and training hadn't quite got off the ground yet. However, if the invasion came in 1942 or 1943, it'd probably be a different story. The Home Guard by then were adequately armed and reasonably trained. Thoughts?

*The Croft's Pike debacle refers to Churchill's order that "every man must have a weapon of some sort, be it only a mace or a pike", at which point the War Office took him literally and ordered 250,000 crude pikes, made of a length of steel tube with a bayonet on the end. It's thought that few were actually issued, and a Home Guard officer, also an MP, said in the House of Commons that the issue of the pikes "if not meant as a joke, was an insult".





Those videos provide a pretty good picture of what the Home Guard looked like early on.