So what exactly is libel in a political context? It's an attack on the reputation of a politician, or more generally a political actor. To be a little more technical, it's a written criticism that would tend to lower the reputation of a public figure in the eyes of a reasonable person. It implies that your attack is malicious. Although the attack is usually in writing, it can occur in other forms such as radio and television broadcasting, as well as social media.

The problem for those of us in the press is that we're stuck trying to strike a balance between the right of freedom of the press, which is an aspect of freedom of speech or expression, and the public figure's right to the property in his or her reputation.

However, if we were American journalists, our situation would be quite different. In 1964 the U.S. Supreme Court redefined libel in New York Times v. Sullivan, holding that malice would be found only where a member of the press attacked the reputation of public figure, knowing the statement was false, or while acting in reckless disregard of its truth or falsity. With such a low standard, the press can just about anything it wants about a public figure.

Canada is more restrictive. If you make a libelous statement, you have to defend yourself -- the onus is you. There are several defences.

The first is justification: The statement is true. You can say Prime Minister Mulroney took bribes from a European businessman, Mr. Schreiber, to award Air Canada contracts to Airbus; but you have to prove it's true.

The second is fair comment: The statement is a criticism on a matter of public interest. You can say Mr. Mulroney took bribers from Mr. Schreiber as long as you have sources, and the Airbus matter has become a matter of public interest. You don't have to prove the truth of the statement.

The third defence is qualified privilege. You can publish what is otherwise a libelous statement to a limited group based on the common interest of its members in knowing about the accusation. So you can accuse Mr. Mulroney and Mr. Schreiber of engaging in bribery, assuming, for example, that Ms. Schreiber has had dealings with your membership and you have reliable sources.

The fourth defence is a relatively new one, approved by the Supreme Court in 2009 in Grant v. Torstar Corp. -- it's referred to as responsible communication on a matter of public interest.

This is a very interesting defence because it's not the same thing as fair comment. The purpose of this category is to expand the definition of a public figure to give greater latitude to freedom of the press in the name of good government. This was done by expanding the notion of matters relating to the public interest. The Court stated:

"To insist on court-established certainty in reporting on matters of public interest may have the effect not only of preventing communication of facts which a reasonable person would accept as reliable and which are important and relevant to public debate, but also of inhibiting political discourse and debate on matters of public importance, and impeding the cut and thrust of discussion necessary to the discovery of the truth."

And further:

"A defence that would allow publishers to escape liability if they can establish that they acted responsibly in attempting to verify the information on a matter of public interest represents a reasonable and proportionate response to the need to protect reputation while sustaining the public exchange of information that is vital to modern Canadian society. The law of defamation should therefore be modified to recognize a defence of responsible communication on matters of public interest."

Ultimately, what this means is that you get the same right to raise questions about the reputation of someone who creates a new public event, such as an annual jazz concert, as you do when covering the actions of a politician. Nonetheless, the communication about the individual or the event must be "responsible."

And here things get murky. A judge or a jury is allowed to consider eight factors in determining whether your statement is "responsible." The Court held the defence will apply where:

A. The publication is on a matter of public interest; and

B. The publisher was diligent in trying to verify the allegation, having regard to:

(a) the seriousness of the allegation;

(b) the public importance of the matter;

(c) the urgency of the matter;

(d) the status and reliability of the source;

(e) whether the plaintiff's side of the story was sought and immediately reported;

(f) whether the inclusion of the defamatory statement was justifiable;

(g) whether the defamatory statement's public interest lay in the fact that it was made in public rather than its truth ("reportage"); and

(h) any other relevant circumstances.

The news about this case is that you have an expanded right to make critical statements about public events and their producers, but the Court is not clear on how many of these criteria must be met to defeat the claim of libel. At the same time, factor (h) makes the defence potentially unlimited, thereby titling the playing field in favour of the journalist. At the very least, you should make these factors a checklist by which to judge your story when writing on a matter of public interest.