A woman has been knocked unconscious in the wake of John Howard's visit to a factory and a shopping centre in Penrith, west of Sydney.

The mishap occurred in the food court of the Penrith Plaza Shopping Centre when the woman fell and hit her head amidst the media scrum surrounding the Prime Minister.

In an eventful visit, John was left with 'air' when one man pulled his hand out of a handshake with the PM, while others shouted insults including scumbag and disgrace.

Earlier, the Prime Minister said the Government was not looking at providing any further assistance to the car industry.

A leaked memo revealed that the four main car makers were looking toward the government to provide more financial support but Howard poured cold water on the idea. He said there comes a point where it is not possible to just keep giving more and more.