What is the tort of passing off in relation to unregistered trademarks? What are the essential elements that a plaintiff must establish in an action for passing off?

With the tremendous growth in trade and commerce, the competitors or other traders tend to imitate the well-known or reputed trademarks by imitating colour scheme or get up or packaging with a view to pass off such goods as goods of the genuine owner. In cases of registered trademarks, the owner can move the court under this Act for the infringement whereas in cases of the unregistered trademarks, the Act recognizes the Common Law remedy of passing off. The tort of passing off is based upon the principle that "no man is entitled to represent his goods as being the goods of another man; and no man is required to use any mark, sign or symbol, device or means, whereby without making a direct representation himself to a purchaser who purchases from him, he enables such purchaser to tell a lie or to make a false representation to somebody else who is the ultimate purchase." The plaintiff, in an action of passing off, has to establish that his business or goods has acquired the reputation and that his mark has become distinctive of his goods among the public at large. He has to establish that there is likely hood of deception or confusion in the minds of the public. He, however, does not have to establish the fraudulent intention on the part of the defendant. Thirdly, he has to establish that confusion is likely to cause damage or injury to the reputation, goodwill and fair name of the plaintiff. He need not prove the actual loss or damage in an action of passing off.