Yes. I have a "good friend" that was in the RAF at the time. The gas masks issued to the civilian population were, in reality, not intended to protect the British from German mustard gas, as they were told, but to protect them while the Brits gassed the Krauts if they landed on the Island.
Furthermore, the Brits had built oil pipelines into either end of the Channel with the intention of flooding the invasion crossing with petroleum, and lighting it on fire with the German invaders trapped in the oceanic inferno.
In short, the concept of the show is entertaining, but highly unlikely. Winston was not going to let Jerry on his Island.
Interesting. Also interesting is that it was the committment to blocking that outcome that made the difference. We need that sort of resolve today. After history is written, it looks easy. But while history is unfolding, we're going to lose people, we're going to lose battles, and we're going to feel hopeless at times. Never forget, never forgive, and resolve to die on your feet. That is the best deterrent.