British celebrity impersonations

There are a couple of episodes where the characters, for one reason or another, break into impersonations of what I have to assume are/were quite famous and recognizable celebrities in Britain and the UK. Being an American, however, I don't recognize any of them. Can other fans help me out?

1. In the ep 'Bob's International Hiccup Centre,' when Bob can't get a laugh during the filming of a TV episode, he breaks into an impersonation: "What a beautiful day! What a beautiful day for sticking a sausage through your neighbor's letterbox..."

2. In 'Jonny Saveloy's Undoing,' Jonny had stolen other peoples' voices and was keeping them in jars. Vince sampled several of the jars and did different celebrity voice impersonations with the 'stolen' voices.

- You may have come on no bicycle, but that does not say that you know everything.