A former ambassador to Indonesia says the execution of the Bali Nine ringleaders has become political for Joko Widodo.

John McCarthy, who was Australia’s Ambassador to Indonesia between 1997 and 2001, told Neil Mitchell that President Widodo was "(stirring) the nationalist pot in Indonesia" for local political capital.

"It was always easy in Indonesia to awaken the nationalist sentiment," he said on 3AW Mornings.

Mr McCarthy also said the matter would inevitably harm our rocky relationship with Indonesia.

"Our relationships have gone up and down with Indonesia over the years," he said.

"It’s bound to rattle it because I think there’s very strong feelings in Australia about this.

"It has not just caused offence to Australians, but to other countries as well."