Can a defendant enter a plea of justification or fair comment in a libel action?

Of course a defendant who has commented upon a matter of public interest may enter a plea of justification, thus waiving the benefit of the public occasion and undertaking the heavier task of proving the truth of all his defamatory words, after furnishing particulars, if required, of the facts on which he relies. And justification, if asserted and proved will, of course, be a complete answer to any demand for damages in the case of any libel. Or he may plead justification and fair comment alternatively, and failing on the first succeed on the second, as was pointed out in Dakhyl v. Labouchere, supra.