United Future is asking the Electoral Commission not to register the Internet Party's logo, because of its colour.
Peter Dunne's United Future party has used a stylised purple U with a green dot in it next to the party name since the mid 1990s.
The Internet Party's logo depicts its name in a purple speech bubble and Mr Dunne says that will look too similar to his own party's logo on the ballot, thereby confusing voters.
"We think we've got a certain proprietorial right to it, but it's for the electoral commission to determine the extent to any confusion."
However, the Internet Party says the logos use different colour combinations and can easily be distinguished.
Chief executive Vikram Kumar says his party had a clear reason for picking its logo.
"It's not only the colour it's the shape of the logo that is entirely different."
Intellectual property lawyer Kim McLeod said the Internet Party is likely to win the argument.
"If I was a betting man I suspect that Mr Kim Dotcom's going to be OK."
He said voters take great care who they vote for and he saw little risk of them being confused on voting day.
The Electoral Commission is considering the objection.