Surrounded by media outside court after the verdict, Banks said: "There's a wonderful 1930s song 'Onto every life some rain must fall', and for me the rain's still falling".
"We were hoping that it would become a very sunny day. We are disappointed with the verdict. We are surprised with the result and now we will come back here on August 1 and I've talked to my legal team, David Jones, QC, about options that I have going forward."
Asked if he had filed a false return, Banks said: "From day one I have told you I would never never knowingly file a false anything let alone a false return.
"What I need to say to you is we have some legal options. Allow me the process of the law and we will be looking at those options and we respect the decision of the judge but we need to have a look at the judgment and take some calls from there."
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Justice Wylie rejected assertions from Banks' lawyer David Jones, QC, that the Dotcom witnesses had orchestrated their evidence as part of a conspiracy theory to bring down the Government.
But the judge could not exclude the possibility that Banks' treasurer Lance Hutchison had used his own knowledge about the SkyCity payment to record it as anonymous.
Banks might have been "careless" in not checking the return and how the SkyCity payment was recorded.
Justice Wylie did not enter a conviction and Mr Jones said there would be an application for Banks to be discharged without conviction at his sentencing.
Banks will be sentenced on August 1. Justice Wylie ordered a pre-sentence report, including an assessment on whether Banks was suitable for home detention.
Banks is not subject to any bail conditions until his sentencing.
Outside court Graham McCready, who originally charged Banks in a private prosecution, said he was ecstatic with the verdict. Despite the toll taken on his health, Mr McCready said his work was worth it.
The judge gave himself a week to reach a decision after hearing seven days of evidence over the electoral return filed after Banks' failed bid for the Auckland mayoralty in 2010.
Before Justice Wylie, with no jury, Banks defended allegations he knowingly received political donations from Mr Dotcom and SkyCity that were recorded as anonymous.
Kim Dotcom. Photo / Richard Robinson
The Crown said Banks' campaign received two $25,000 donations from Megastuff Ltd on Mr Dotcom's behalf in June 2010 and $15,000 from SkyCity in May that year.
Banks engineered the situation so the donations would appear to be anonymous and were recorded as so by his campaign treasurer.
Mr Jones said the charge was denied and Banks had no knowledge of the payments.
Ahead of this afternoon's verdict, Prime Minister John Key said: "whatever the result the government will still command a majority and there's no impact on our capacity to govern. So we have more than enough votes in terms of confidence and supply we have a relatively short number of weeks to run until the House lifts".
He did not believe a guilty verdict would taint the Act brand.
"You've got to remember the current court case relates that were undertaken before he was a member of the Act Party and while he was the Auckland Mayor.
"I don't think that reflects on either the Act Party or our relationship with the Act Party."
Mr Key said he was not aware of any legislation his Government would have relied on Mr Banks vote to pass between now and the election.
Should Mr Banks be convicted, forcing him out of Parliament, it is unlikely a by-election in Epsom would be held to fill his seat because it is being vacated within six months of a general election.
The Government could seek to hold a by-election but would require a 75 per cent majority in Parliament to do so.
