UPDATED 5.19pm It's not unusual for politicians to have objects thrown at them during Waitangi commemorations, but this one's a little different.

Economic Minister Steven Joyce had a large pink sex toy thrown at him as he left the iwi leaders forum, hitting him in the chest.

Mr Joyce said he didn't see the pink rubbery object until it hit him.

"I think on the face, well it did on the face, yes, umm, and I wasn't aware what it was until afterwards."

The woman who threw the object was apparently protesting the Trans-Pacific Partnership, as she shouted that it was for taking away New Zealand's sovereignty.

Labour leader Andrew Little says it’s not clear what the anti-TPP protestor expected to achieve.

"It's a creative item I guess to throw at a politician. Perhaps the person throwing it thought there was a message in it. I can't imagine what that would be."

"The connection between sexual devices and sovereignty is not immediately apparent to me, but I think we shouldn't underestimate the fact that people are very hot under the collar about TPPA."

Steven Joyce is hopeful today's incident won’t be what his political career is remembered for.

"Well I'd rather hope not, I'd rather hope that I've done a few things that made a contribution to New Zealand, and this will be just one of the little background things," he said.