In the UK for an arrest to be legal, it must meet section 24 of the Police and Criminal Evidence Act 1984(PACE).
Arrest without warrant: constables
(1)A constable may arrest without a warrant—
(a)anyone who is about to commit an offence;
(b)anyone who is in the act of committing an offence;
(c)anyone whom he has reasonable grounds for suspecting to be about to commit an offence;
(d)anyone whom he has reasonable grounds for suspecting to be committing an offence.
(2)If a constable has reasonable grounds for suspecting that an offence has been committed, he may arrest without a warrant anyone whom he has reasonable grounds to suspect of being guilty of it.
Now if your arrest is unlawful, then that will be determined not by you, but by the COURTS. The Court will find you not guilty, you cannot make the determination yourself, neither can your friends and family, nor can David Cameron. Only the Courts have that authority
If your detention or arrest isi unlawful, then it will be deemed as so, so long as you did not use unreasonable force in trying resist arrest.
Another words, even in the UK, you can be arrested even if you are certain of your own innocence, but that arrest will only be deemed unlawful by the courts, not by you! Police and Criminal Evidence Act 1984
There are many laws in pakistan that are unjust. The constituion is chalk full off injustice which Imran Khan doesnt touch because its not in his interest. But regardless, the law does exist, and if its unjust, then its for the Courts to decide, not for you or Imran Khan.
Citizens in a democracy have power to elect their leaders. They dont have the authority to attack parliament or break the law, or hinder justice. We as a society, one of the sacrifices we make for living in an organized society is that we give authority to the police, to the courts, to the govt to run that society. If you or I try to then wrest by force that power, then we are in the wrong. The police have the authority to use force, even lethal force if it comes down to it. Whether that force is justified again is determined by courts, not you.
Pakistan’s system is flawed but imran Khan isnt going to fix it with his protest. The only way to fix it is to allow the system to mature and evolve. That wont happpen through these sit ins and unreasonable demands. Your doing your country far more damage with these protests then helping,
What would the govt have been sacked for? Corruption has to be proven. If its proven in court, then Imran will declare himself vindicted. If its not proven, then Imran will claim the system is corrupt and everything should be destroyed. You cant win with someone that unreasonable.