Canada's first parliamentary budget officer is raising concerns with proposed Liberal legislation that he says would be detrimental to the office's independence.

The budget implementation bill, introduced on Tuesday, would make the federal watchdog an independent Officer of Parliament, set the officer's term at seven years, ensure the office has expanded access to data and enable it to estimate the costs of any election platform proposal — at the request of political parties.

But Kevin Page, who was PBO from 2008 to 2013, is particularly worried about a proposal mandating the PBO to submit its annual work plans to the Speakers of the Senate and the House of Commons for approval. He says the PBO's work risks getting mixed up in partisan games.

"When I was the parliamentary budget officer we were often talking about difficult issues of the day, costing wars, costing crime bills, fighter planes. And I ask myself when I look at the legislation; would we still be able to do this? and my concern is that we would not," he told CBC Radio's The House host Chris Hall.

"I worry Speakers would say, 'No we don't want you to do that.'"

While not against submitting a work plan for the sake of oversight, Page said he's not convinced a partisan position like the Speaker of the House should be the one to rubber stamp it.

"My theory, based on experience, is that it's a control feature. It definitely could be used to constrain the office and take a way the independence," said Page, noting his relationships with the Speakers between 2008 and 2013 were "difficult."

"Right out of the gates, before we were even six months old, I was getting letters from the Speakers saying that you are exceeding your mandate, that we don't like the way you're releasing documents."

Limits on requests to PBO

Another point of contention is a section in the more than 300-page document that Page says appears to limit who can put in a request to the PBO to provide cost estimates on government programs.

The changes would only allow MPs to ask for estimates on legislation they've introduced. It would also accept requests from committees, where memberships are usually weighted in favour of the government of the day.

The bigger question is; are we better off with this legislation? and to be honest I'm not sure that we are. - Kevin Page

Page points out it was the NDP and Liberal members, then in opposition, who asked him to review fighter planes.

"They asked us, like we really need to wrap our heads around this fighter plane, can you take on this project?" he recalled.

"We have a Liberal government now that wants to increase spending quite significantly on infrastructure and other files...Why wouldn't we want the parliamentary budget officer to start assessing, like, what do we know about the performance of that infrastructure?" he asked.

Summer break could stall reports

The proposed changes would also prevent the PBO from making a report public until a day after it provides it to the parliamentary committee that requested the research or to the Speakers, a possible problem during break weeks.

"Parliament might not be sitting but the PBO might need to put out something saying, we just had a major economic event. Like OPEC just made a big decision or something big happened in the United States," said Page.

"The bigger question is: are we better off with this legislation? And to be honest, I'm not sure that we are."

Page did say he's encouraged by a proposal to allow the office to cost election promises and he's happy the tabled bill fulfills a 2015 election pledge by making the PBO an Officer of Parliament.

"We get independence on one hand in this legislation and we take it away with the other," he said. "I hope we will see amendments."