PM refuses to rate his first 100 days

Malcolm Turnbull is declining to to put a rating number on his prime ministership so far.

Mr Turbull was asked about his first 100 days in office - which he marks on Christmas Eve - during a question-and-answer session at a Lifeline lunch in Sydney on Monday.

"I'll leave the marking to you and the other 24 million Australians that have got a keen eye on how well I'm doing my job," he told host Mike Munro.