No it's actually not different. It's trivial to prove with a bit of motivated reasoning, here watch this:
(for people not watching it closely, the following is not my opinion but a demonstration how one could prove censorship of political opinions is necessary if one is allowed to censor "offensive speech").
UK is a democratic country. In a democratic country, the government is elected by people, and can exist only while people support it. Not literally everybody, of course, but a significant part of people must support any government system for it to be able to function as a democratic society. By attacking the government, you offend these people and their deepest held beliefs, and imply that they are either not smart enough to figure out how the government should be, or are too lazy to go and vote for a proper government. Moreover, if you argue that a particular elected official is stupid, or corrupt, or bigoted, or criminal - you also imply people who voted for that person either are OK with these things or are too stupid to recognize them (at least if these things were known before the election). Both can be deeply offensive to people. Of course, some people would be OK with being called bigots or idiots, but many would take it as a gross offense. Similarly, calling their chosen representative such words would be possibly a less personal, but no less hurtful offense - after all, if somebody insults your friend, you'd be also hurt as if they'd have insulted you, wouldn't you? Maybe a bit less, but same goes for your representative.
Thus, it is clear that political speech can be grossly offensive. Moreover, I would go further and claim that it is more offensive than, for example, a racial insult. You do not choose your race, so if somebody insults you on the base of your race, it has very little to do with you personally - it's not directed at you as a person, but at a vague concept of race which largely exists in the mind of the speaker and nowhere else. You could shrug it off as empty words having nothing to do with you specifically. Insulting your political creed goes much deeper to the core of your identity and hurts on much more personal level - it is offending part of your identity that you yourself chose and built!
Thus, one can consider proven that criticizing the government is as much and maybe more hurtful than regular slurs and insults, and must be prosecuted at least as harshly.
(for people not watching it closely, the above is not my opinion but a demonstration how one could prove censorship of political opinions is necessary if one is allowed to censor "offensive speech").
The solution of this problem is that government should not ban any speech (with obvious and well-known exceptions, blah blah) and not be allowed to determine what is "offensive" and prosecute people for that.