Article 21 of the Constitution of India states, No person shall be deprived of his life or personal liberty except according to procedure established by law. Hence ensuring legal aid to everyone is necessary for ensuring substantive equality. Legal Aid means giving free legal services to the poor and weaker section of society who cannot afford to take the service of advocate to conduct a case or any legal proceeding before the court of law, any judicial authority or before any judicial tribunal.

Article 39A of the Constitution of India provides that State shall secure that the operation of the legal system promotes justice on a basis of equal opportunity, and shall in particular, provide free legal aid, by suitable legislation or schemes or in any other way, to ensure that opportunities for securing justice are not denied to any citizen by reason of economic or other disability.

Legal aid strives to ensure that constitutional pledge is fulfilled in its letter and spirit and equal justice is made available to the poor, downtrodden and weaker sections of the society. The preamble of the Indian constitution basically aims to secure to the people of India justice - socio- economic and political. Article 21 clearly says that every person has an equal right to life and liberty except according to the procedure established by the law.

The State shall secure that the operation of the legal system promotes justice, on a basis of equal opportunity, and shall, in particular, provide free legal aid, by suitable legislation or schemes or in any other way, to ensure that opportunities for securing justice are not denied to any citizen by reason of economic or other disabilities.

In M.H. Hoskot v. State of Maharashtra, the Supreme Court said while holding free legal aid as an integral part of fair procedure the Court explained that the two important ingredients of the right of appeal are:

1. firstly, service of a copy of a judgement to the prisoner in time to enable him to file an appeal and
2. secondly, provision of free legal service to the prisoner who is indigent or otherwise disabled from securing legal assistance.

This right to free legal aid is the duty of the government and is an implicit aspect of Article 21 in ensuring fairness and reasonableness, this cannot be termed as government charity. In other words, an accused person at lease where the charge is of an offense punishable with imprisonment is entitled to be offered legal aid, if he is too poor to afford counsel. Counsel for the accused must be given sufficient time and facility for preparing his defense. Breach of these safeguards of a fair trial would invalidate the trial and conviction.