Prime Minister Tony Abbott says he regards Adelaide as the world's most liveable city.

Speaking at the South Australian Liberal Party’s annual meeting on Saturday, Mr Abbott said the city had “great people, a great climate, terrific restaurants, art and culture”.

“This city has got everything going for it except the strong economy that the people of South Australia deserve,” he said.  Mr Abbott said it was important to SA for the new coalition government to scrap both carbon and mining taxes.

He said as long as those two measures remained in place there would be a “permanent handbrake” on the local economy.

The prime minister said without the carbon tax and the mining tax the chances of BHP Billiton proceeding with its major expansion of the Olympic Dam uranium and copper mine would also be enhanced.

“I can’t guarantee that without the carbon tax and without the mining tax the Olympic Dam mine expansion will go ahead,” he said.

“But I can guarantee that with the carbon tax and with the mining tax, it will never happen.”

BHP Billiton put the $30 billion expansion on hold late last year ahead of advancing new mining technology to make the project financially viable.

On Saturday Mr Abbott also pledged to help fund the long-awaited north-south road corridor through Adelaide under a future Liberal state government.