Act Leader John Banks maintained he had done nothing wrong after a High Court judge today reserved his decision over whether to commit Banks to trial for allegedly filing a false election return.

Banks left Auckland's High Court through a rear entrance, avoiding waiting media, before being pursued down a nearby street where he insisted he "only [does] good'' things.

It came after the court heard arguments from Banks' lawyer, David Jones, that a District Court judge had made errors of fact in committing the politician to stand trial.

However Solicitor-General Michael Heron QC, who has taken over the case from private prosecutor Graham McCready, said any factual errors were matters to be decided at trial, and not by judicial review.


Mr Heron said District Court Judge Phil Gittos did all that was required by law in committing Banks to trial.

Mr Jones told the court that Judge Gittos had erred in his decision by saying that Kim Dotcom's donation of $50,000 was given directly to Banks, that he had incorrectly added up the number of donations in the electoral return, and said Banks had "glanced at'' the papers, when the evidence given by his campaign finance manager was that he "might have glanced,'' but did not read the papers.

"These are factual findings which clearly are wrong, and which must have affected the reasoning process of the judge and the conclusions that he later drew,'' Mr Jones told the court.

He said the issue was whether Banks knew there was a specific false statement in the return at the time it was sent, "and that is not available on the evidence before the court''.

However, Mr Heron said the Crown's case would be that Banks had encouraged the donations, knew they were being made, and made it clear he intended them to be anonymous.

"So whether or not he gave the return a great deal of scrutiny won't be at the heart of the Crown case,'' he said.

After the hearing Banks said he still intended to stand for his Epsom seat in next year's general election, but admitted it would be difficult if the trial went ahead.

"I think it would be problematic if I had a trial at the end of next year for my political career, but we make that decision when we get to it, and the first base is next week.''

Should the trial go ahead, he was "looking forward to being exonerated''.

"I've spent a lifetime of doing good, a lifetime of trying to balance my family ledger, a lifetime of making a difference for people, and a lifetime of contributing to this country. I only do good. I don't do bad things.''

Justice Paul Heath said he expected to deliver his decision by early next week.