Flaw at the heart of the film
Normally when I watch a film I try to suspend my flaky analytical powers and accept the story as presented. But the immediate and insurmountable problem here is that not for one minute did I believe they would cast Anna Neagle as a Nazi sympathiser. It was simply asking too much of this particular member of the audience to not only suspend his disbelief but to lock it in a sealed steel case and sink it in to the depths of the Atlantic.
But I did enjoy the film for what it was - well cast, well acted with a decent, if predictable, story and the requisite number of clichés.