The Sydney Habour ferry recently named Ferry McFerryface has bizarrely become a NSW election issue.

Maritime Union of Australia workers are boycotting the ferry over what they say is a "disrespectful" name and now Opposition Leader Luke Foley says he'll scrap the name if Labor wins government in early 2019.

"If Labor's elected to form the next government in NSW I will dump this silly name," Mr Foley told AAP in a statement on Friday.

"We will rename the ferry and we will engage with the public to find a suitable name which recognises a prominent Australian."

The name was announced on Tuesday and immediately angered many - including the union which argued Ferry McFerryface was insulting and a "bad joke" that would quickly wear thin.

NSW Transport Minister Andrew Constance on Friday was forced to admit the name wasn't on the original list of 36 put forward by a panel of four distinguished Australians.

The five other new Emerald class ferries have been named after Australian doctors and indigenous leaders.

But Ferry McFerryface was chosen for the sixth ferry by the minister himself "based on the number of nominations received from the public".

"The honorary panel made recommendations but the final decision on each was for the NSW government," Mr Constance told AAP in a statement.