Local governments' debt is an issue that should draw “great concern”, as the governments “have no idea” how large the debt exactly is, Yu Yongding, a former member of the Monetary Policy Committee of the People's Bank of China, warned on Wednesday.

“Why I am so concerned about the debt issue? Because based on my experience of dealing with local governments, I am skeptical whether they are willing and are able to repay the debts,” Yu said at the Netease Annual Economist Conference.

He also cast doubt on China's property boom, saying property investment's share in total investment is too high. On one hand, China's overall house supply is abundant. On the other, a considerable number of urban residents cannot afford a house because of skyrocketing prices.

“The largest problem for China's property market is it consumes too many resources,” Yu said.

He also proposed levying a property tax, as an efficient way to force people with multiple houses to rent out their inventory.

Xu Shanda, former deputy director of the State Administration of Taxation, said at the conference that he was glad to see the Politburo meeting on Tuesday did not mention “curbing the property market”, as it always had before.

“This is a very, very important message. Instead of restricting home purchasing, the meeting mentioned ‘unleashing' demand, which showed a different approach,” Xu said.

He suggested the government should take different approaches toward affordable houses, ordinary homes and luxury houses, easing restrictions on purchasing luxury houses.