UPDATED 11.32am: Horowhenua's mayor is labelling the Local Government Act as idiotic.

At a council meeting last night, Michael Feyen announced he's changing his deputy mayor back to councillor Ross Campbell.

He's done so after councillors originally removed Mr Campbell as deputy and voted in councillor Wayne Bishop.

However, Horowhenua District Council acting chief executive Monique Davidson has this morning released a statement saying Wayne Bishop is still deputy mayor.

She said the only way to change the deputy now is by majority vote of council, not by the mayor alone.

Yesterday, Council project coordination manager Mark Lester said advice he's received said the mayor's move isn't legal.

"That would be considered to be a perverse use of the mayoral powers to do so, and it would also go against the democratic process given that the Council have made a decision by majority to appoint a deputy mayor."

Mayor Feyen said he disagrees with that.

"Part of the reason I'm doing this is so the government actually does something about this idiotic law, it's an absolutely idiotic law."

"I'm just going to stick with my words and take the consequences later on, if there are any," said Mayor Feyen.

Mayor Feyen said he did not trust Mr Bishop while making the announcement to reinstate Mr Campbell as deputy.

His announcement was met immediately by a point of order challenging his authority to make the move.