According to the NZ Herald, Chris Cairns has now been formally charged.
The article is slightly confused, as it mentions the offence of perverting the course of justice and the offence of perjury. The two offences are not the same, although from Cairns' point of view it is a distinction without a difference. Either way his conduct in the libel trial against Lalit Modi is being challenged and thus the credibility of his denials about match fixing is in issue.
Both perjury and perverting the course of justice concern whether or not the process of justice has been obstructed. Perjury is committed when a person lies under oath, either while giving evidence in court or in sworn statements presented to the court. Perverting the course of justice can be committed by actions such as hiding or destroying evidence material to a case.
In many trials perjury is technically committed: judgments often state that a witness' evidence was 'not credible', or that the witness was clearly trying to tailor their evidence to suit their side of the case. Prosecutions do not automatically follow, especially if the evidence was not material to the case or at least the lie did not affect the outcome (say because the witness' side lost the case, or won on grounds independent of the dodgy evidence).
A prosecution is usually only brought where there has been a very serious breach. Jeffrey Archer's case was a classic example: his entire case was brought on a lie - abusing the very notion of justice, as well as wasting millions of pounds of both public and private money.
Much the same applies to perverting the course of justice: a prosecution would only follow in serious cases.
I would expect therefore that the charges against Cairns will be based on serious allegations. But it is important to stress - as I have before and will continue to do - that that does not mean they have been proven yet. Especially where the squalid world of match-fixing is concerned, the truth will always be difficult to ascertain. Cairns is innocent until proven guilty, and if nothing else, as he himself has stated, at least he now has the chance to defend himself in a proper legal forum, with full disclosure of evidence and cross-examination of all witnesses.
Moreover, although there is no material difference between English law and New Zealand law in this area, it seems to me to be an advantage that the trial is taking place in England, where it is likely none of the jury will have heard of Cairns (unless they are cricket fans). The story has been reported in England but only on the sports pages. Thus, Cairns will at least get a fair trial instead of the trial by media he has had to endure for the past few months in New Zealand.