I have written elsewhere about our "elaborate codes for acknowledging and regretting the unhappy necessity of imposing burdens on our peers".
Anglo-American culture is intensely, almost pugnaciously individualistic. Except in an evident emergency, no one is felt to be entitled to demand a particular action of someone else, and we resent such demands, even by (or especially by!) people who are entitled to make them, like policemen or bosses.
Consequently, we rarely use frank imperatives like "move", "step aside", "let me pass", even softened by "please". If you look at the language suggested in the Comments you'll see a number of linguistic strategies for 'distancing' demands:
- introducing the demand with an acknowledgment that you're imposing on your addressees and intruding on their privacy (Excuse me or *I beg your pardon)
- casting the demand as a questions and as a hypothetical (Could you please move?, Would you let me pass?)
- casting the demand as a favor conferred by your addressees (I'd be so grateful ... I need to get past ... thank you!)
(Any of these can of course be uttered in a tone and with a demeanour which negates the distance and the politeness, so you have to keep your voice friendly and apologetic, and suppress any vexation you actually feel.)
In your particular situation, these may accompany physical actions like actually pushing your way through the people blocking your way; as long as you perform those actions in a manner which makes it clear that you are trying to avoid unnecessary contact and force, people will not ordinarily take offense.
All of this assumes that your addressees are ordinary folk, eager to accommodate your need. There's always a chance that you will encounter self-centered Yahoos who think it's funny to impede others, or thugs looking for victims to intimidate and bully. But there's really no linguistic strategy to meet situations like that—as they say, "That's life in the big city".