I know the writer's did not identify which party Hacker represented and that it was about government not politics but did anyone ever believe Hacker was anything other than a Conservative (albeit a wet one, as the description went in those days)?
Well, the Conservatives were in government at the time...but on the other hand Hacker was an "idealistic" former journalist who wanted to change the system "for the better", etc.
He had traits of "stereotypical" MPs from both side of the House, which was of course, the whole point...to take the "edge" off the satire, so that the show becomes a comedy about British government in general, rather than just one political party. That's a great way to avoid alienating roughly 50% of your audience.
It's generally been put forward that Hacker and "The Party" were from the middle, as many of the politicians say in the interviews included on the Yes Prime Minister set, which were conducted before the airing of "Party Games," which set up Hacker becoming Prime Minister. Most suggested the SDP.
Fortunately, Ah keep mah feathers numbered for just such an emergency!