As a career politician, Julia Gillard is used to having insults flung at her. But it appears she is also getting used to having sandwiches thrown too.

Another sandwich was thrown at the Prime Minister on Thursday, during a school visit in Canberra.

The bread-based missile, which appeared to contain salami and a butter-like spread, was lobbed by an as-yet unidentified culprit in a crowd of students. It is reported to have hit her arm before falling to the ground.