Anyone who thought Tony Abbott was unelectable has been proven foolish, former prime minister John Howard says.

Mr Howard said Mr Abbott will do a fantastic job as prime minister.

"All those ridiculous people who said he was unelectable should understand how foolish they were to underestimate him," Mr Howard told the Seven Network.

"I can't speak too highly of what a wonderful job Tony Abbott has done."

Mr Howard said Mr Abbott and his team would serve the country well.

"Tony Abbott will do a fantastic job, we will look after the security of this country, we will look after the public money," he said.

He said Labor's defeat was deserved.

"This has been a very unstable, incompetent government."