I'll be out until later this afternoon so I won't be able to confirm guesses or provide clues for a while. But here it is anyway. Good luck.
Okay, I'm back and no one is guessing so... 1st clue - It's a British Comedy.
*****CLUE NUMBER TWO*****
Let's do a roundabout clue. Recently, Marilyn did a short post about slang featuring a movie that was remade. It's musical remake won Best Picture. The star of our Name That Movie is in that musical remake and in it he must get somewhere... on time! Hell, he even sings a song about it. And did I mention the Bonus Round Name That Movie is a British Comedy. A very silly British Comedy.
*****CLUE NUMBER THREE*****
The main targets of the film's gentle satire are the British Government and Nationalism.
*****We have a winner: Marilyn got it right. The mystery clip is from the 1949 comedy Passport to Pimlico. Congratulations to Marilyn.