TONY Abbott has lashed out at the government for flinching in its support of Israel, using his first major speech of the campaign to pledge fidelity to the Jewish state.

Addressing an Australia-Israel Chamber of Commerce lunch in Melbourne, Mr Abbott drew applause when he signalled that the Coalition would ''never support a one-sided UN resolution against Israel to curry favour with an anti-Israel authority''.

He also suggested the government overreacted in its response to the Israeli Defence Force's attack on an aid flotilla that killed nine activists.

"Of course the Israeli government does from time to time make mistakes," Mr Abbott said. "What government doesn't from time to time make mistakes?

"But Australians should appreciate that a diminished Israel diminishes the West; it diminishes us. And I have to say that I am a little disappointed that given the deep affinity between the Australian people and the Israeli people that the current Australian government has somewhat weakened our longstanding bipartisanship on Israel.