After checking, no, it really wouldn't (although Parliament seats weren't necessarily divided very fairly before the 19th century reforms, what with rotten boroughs and all that).

Apparently the colonies had around 2.5 million people by that time, with Great Britain at only about 7-8 million. I'd have estimated the former number much lower, and the latter at least twice as high... that does suddenly shed a new light on the American colonists' victory in the Revolution.

According to one of the websites I'm looking at, Philadelphia was also the 3rd largest city in the British Empire, after only London and Edinburgh...