Federal Liberals have accused Mr Shorten of resisting proper scrutiny by avoiding more than the two already-scheduled leaders' debates.

Mr Shorten and Prime Minister Scott Morrison are due to go head-to-head in Perth on Monday, televised by the Seven Network, and Brisbane next Friday on Sky News.

The opposition leader released a letter on Friday evening seeking a televised debate at the National Press Club in Canberra on May 8.

It would involve journalists from Nine, the ABC and another media outlet on a panel.

Mr Shorten questioned where some government ministers have been during the campaign and why they haven't been allowed to debate with their Labor counterparts.

"Mr Morrison is keeping many of his ministers in witness protection because he's too embarrassed by them or too afraid of what they'll say," he said.

Labor also points out Mr Shorten will be doing a solo appearance on the ABC's Q&A program on May 6 and suggests Mr Morrison do the same.

Mr Morrison earlier took aim at the Labor leader's strategy.

"Bill Shorten seems to be treating this election campaign as if it is some sort of coronation for him," the prime minister told reporters in Townsville.

"I see this election campaign as the opportunity for me to talk about the plan that I have for Australia."

Australian Associated Press