Former prime minister John Howard has blamed Kevin Rudd for Australia's economic and border protection problems as he rallied the Liberal troops at the party's Victorian campaign launch.

Mr Howard received a standing ovation from thousands of Liberal supporters as he took the stage in a presidential-style rally at the Melbourne Showgrounds.

Surrounded by an audience waving Liberal placards, Mr Howard said the Labor Party had destroyed what he called the great position the Liberal Party left Australia in.

He said when he left office in 2007 the boats had stopped and the country's economy was the envy of the world.

He said Prime Minister Kevin Rudd was a "great policy chameleon" who had no policies of his own and changed his stance on issues.

"He doesn't have a firm position, he has a position that he thinks is the most responsive and effective to the questions of the moment," he said.

"And there is no doubt in my mind that the greatest single policy failure of this government has been its failure on border protection."