What TV show or film is this line from?!

Question:

What TV show or film is this line from?

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"Ladies and gentleman, we are at war."

The line has just popped into my head and I can't for the life of me remember where I heard it. Could possibly be Dr Who, but I'm really not sure.

Any help is really appreciated.

Answers: Dr. Who, either Day of the Daleks or Parting of the Ways Sounds cheesey enough to be from "Independence Day" Could be anything. Bit old but- Dad's Army?

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