... while in the case of exploitation and compulsion by the ring leaders of a 'begging racket', the "beggar" who begs under compulsion of fear for bodily harm from them would have the defense of duress, where the "beggar" takes to begging compelled by poverty and hunger, he would be entitled to invoke the defense of necessity. The common feature of both defenses being the element of involuntariness or, shall I say, lack of legitimate choices. It is the absence of legal alternatives that provides the defense of duress or necessity. This is aptly described by Dickson J giving the majority opinion of the Supreme Court of Canada in Perka v. The Queen  2 SCR 232 in the following manner:
Given that the accused had to act, could he nevertheless realistically have acted to avoid the peril or present the harm, without breaking the law? Was there a legal way out? I think this is what Bracton means when he lists "necessity" as a defense, providing the wrongful act was not "avoidable". The question to be asked is whether the agent had any real choice: could he have done otherwise? If there is a reasonable legal alternative to disobeying the law, then the decision to disobey becomes a voluntary one, impelled by some consideration beyond the dictates of "necessity" and human instincts.
The discussion on begging as protected expression under Article 19(1)(a) is also fascinating. Usha Ramanathan discusses our jurisprudence around begging laws in this excellent piece. (Hat-tip t0 Siddhartha and Srinivasan)