The Court of Appeal has reserved its decision on John Banks' battle to clear his name of filing a false electoral return.

The former ACT MP has brought new evidence forward supporting his argument donations weren't discussed at a lunch he had with Kim Dotcom a few days before he signed donation cheques.

Mr Banks told journalists gathered outside the Court of Appeal he accepts he may have to go on trial again if his appeal is upheld.

He's sticking by what he said three years ago, that he's never signed a false electoral return.