CAKED IN CRITICISM: Mayor Len Brown leaves Auckland University with remnants of a lamington stuck to his shirt.

Auckland Mayor Len Brown was the target of a lamington attack by an angry supporter of Ports of Auckland workers.

Brown had been speaking to students at Auckland University when the incident happened just after 1pm.

It's understood he was targeted by a dreadlocked man, angry with Brown's lack of intervention in the Ports of Auckland industrial dispute.

On Wednesday port management announced it would make 300 striking workers redundant following a drawn out disagreement over working conditions.

Brown has been criticised for not intervening in the bitter dispute.

Brown was carrying out one of his regular Mayor in the Chair events, where he speaks one-on-one to locals.

Auckland University Student Association vice president Daniel Haines says Socialist Aotearoa members were chanting "Len Brown step down" and expressing their distaste for what happened yesterday.

He says the mayor, who was due to leave anyway, stood up and "politely walked away".

He says the rest of the Mayor in the Chair event had been constructive and students had talked to Brown about general Auckland issues like public transport and bus lanes.

Haines says Mayor in the Chair is an initiative the association supports and hopes Brown will return.

"AUSA supports the wharfies but we don't support throwing a lamington at Mayor Len Brown at all."

A spokesman from Brown's office says he had spoken to about a dozen people during the hour and made a point of speaking to at least three members from the Maritime Union.

He says Socialist Aotearoa members and Australian and New Zealand members of the Maritime Union had descended on the university today knowing Brown would be there, and were carrying placards.

The spokesman understood the man who threw the lamington was also associated with the anti-capitalist Occupy Movement.

Brown's office confirmed he would be back.