The Parliamentary Budget Office has costed the proposal at the request of independent MP for Indi Helen Haines, who will introduce a bill to parliament later this month to establish such a watchdog.

Under the proposal two new government agencies would start from July next year.

One would be the Australian Federal Integrity Commission, an independent agency tasked with implementing a national integrity strategy and preventing corruption in federal public administration.

The other would be the Office of the Commonwealth Parliamentary Standards Commissioners, which would create a new register of interests for all parliamentarians and parliamentary code of conduct.

The costing of $187.3 million relates to the 220 or so staff required for both agencies, as well as operations.

But it doesn't include accommodation costs due to the "high level of uncertainty" around how much it would cost to construct, lease and fit-out buildings.

Ms Haines is urging the government to let parliament debate her bill, calling on two coalition MPs to cross the floor when it's introduced.

"I've written my bill so that it learns from the experiences of state-based corruption commissions," she said.

"AFIC is a fair and balanced model that has all the powers it needs to do its job, but also appropriate safeguards. It's neither a star chamber nor a toothless tiger."

Calls for a federal integrity commission have grown this week due to the NSW corruption watchdog's investigation of disgraced Wagga Wagga MP Daryl Maguire.

It's been nearly two years since the Morrison government promised to develop draft legislation for a Commonwealth Integrity Commission.

The government now argues it's been too busy dealing with the coronavirus pandemic to establish the watchdog as promised.

But months before the coronavirus sparked a global health emergency the government twice shut down debate on a Greens bill setting up such a commission.

The Greens bill passed the Senate in 2019, but the government stalled its progress in the House of Representatives last September before doing so again in February and June.

Labor has flagged it would work with crossbenchers to get a commission.

Australian Associated Press