Police were called to a protest outside an official government function in Canberra this afternoon, but no arrests were made.

A group of approximately 2000 people surrounded the doorway of a restaurant near Old Parliament House, where the Prime Minister was handing out medals to Emergency Service representatives.

Opposition Leader Tony Abbott was also present at the function.

The group had come from a march related to the 40th anniversary celebrations of the Aboriginal Tent Embassy nearby.

They stood outside the restaurant, calling out the politicians who left with a police escort when Prime Minister Julia Gillard stumbled in the commotion.

She was then bungled into a car.

Embassy co-founder Michael Anderson said the protests were sparked by comments Mr. Abbott had made that its existence needed to be re-considered.

Protester and Brisbane Indigenous media personality Tiga Bayles says he was in the middle of the protest group.

Mr. Bayles says the situation was tense and the police were overly physical, punching a young man.

"Young, inexperienced police came in there with big adrenalin rushes and stuff like that and started to get physical.

"They just didn't know what to do and how to handle the situation. They were lucky they had some older police there that kept control of their ranks.

"Our people - there was enough of us older ones with the Embassy mob to keep things calm there.

"It was very tense and it was close to...it just could have blown up in people's faces."

Mr. Bayles has been involved with the Tent Embassy since 1972.