The impending avalanche of legislative change as a result of government initiatives has caused business uncertainty to jump substantially in the past six to 12 months, according to Tyndall Investments.

But some companies were more susceptible to the changes than others, and the assessment of risk to investment portfolios stemming from government policies should take a more prominent place in research processes, the fund manager said.

"The current government is creating all sorts of business uncertainty," Tyndall head of research Roger Collison said.

"What we are finding at the moment is that this risk is much higher than it normally is.

"There is always risk, but the combination of the GFC (global financial crisis), a government coming to the end of its term and a government which has got a different mandate means that there is a lot of change about."

The most obvious example of a company's increased risk profile brought about by government policy is Telstra, which the government would like to see split into separate businesses to decrease its dominance of the telecommunication sector.

But government risk had become more widespread, especially in the healthcare, superannuation and banking industries, Collison said.

He said an example was the current review of competition in the pathology collection industry, which could affect healthcare companies, including Primary Healthcare, Healthscope and Sonic Healthcare.

The government plans to remove the restrictions on the number of collection centres a pathology provider can operate to give smaller operators a better chance to survive.

But Collison said that would also drive down the profitability of the sector as a whole.

"That is not good policy," he said.