Just two days after PM Julia Gillard called a snap federal election for August 21, opposition leader Tony Abbott made the first move to woo Jewish voters.

The Liberal leader told the Australia Israel Chamber of Commerce in Melbourne that the Labour government weakened Australia's longstanding bipartisan support for the Jewish state.

"We would never overreact to any international incident," he said in an apparent reference to the Australian reaction to the flotilla incident and the forgery of four Australian passports used in the assassination of a senior Hamas leader in Dubai in January.

Mr Abbott added: "We appreciate that Israel is under existential threat in a way that almost no other country in the world is. Australians should appreciate that a diminished Israel diminishes the West; it diminishes us."

Ms Gillard, who became PM in June, was accused of being too soft on Israel by the former Australian ambassador to Israel, Ross Burns. She has visited Israel twice and was staunchly supportive of Israel during Operation Cast Lead.