In fact, shortly after the NDP unveiled the document last week, Page was quoted referring to it as a "Swiss-cheese fiscal costing platform."
But Page revealed Tuesday that he is indebted to party Leader Tom Mulcair for having his back when his office's budget was slashed.
"My connection to Thomas Mulcair is a personal one," Page said as he introduced Mulcair for a speech on the state of Canada's economy at the University of Ottawa.
Page, who is now the Jean Luc Pepin Research Chair at the university's faculty of social sciences, recalled to the student-dominated audience how the parliamentary budget office came under attack from a Conservative-dominated Commons committee.
The PBO, created in 2006 under the Federal Accountability Act, had become a thorn in the government's side after it released several reports that contradicted what the Conservatives were telling Canadians about some big-ticket issues, such as the true cost of the war in Afghanistan, budget deficit projections and the seriousness of the 2008 recession.
In reaction to the reports, the government attempted to starve the PBO of the resources it needed to do its job by cutting the office's budget.
"I found myself in front of a parliamentary standing committee fighting for the survival of the office," Page recalled.
"Mr. Mulcair, (who) was not even a member of the committee, went to the meeting and fought to have the budget reinstated," he said.
When the committee's final report recommended that all of the PBO's reports be made confidential, Page had had enough. He was ready to resign, he said.
"Mr. Mulcair phoned me and told me not to quit," Page said, adding that Mulcair's reassurances convinced him that Canada's institutions are far bigger than any one person, and that it's important to hold to your principles.
"I wouldn't be here today if it wasn't for Mr. Mulcair."
That doesn't mean Page has endorsed the NDP as it campaigns to unseat the Conservatives in the Oct. 19 federal election.
Earlier Tuesday, in an email to The Canadian Press, Page wouldn't say directly which party he thinks is best to govern.
"As a former budget officer, I will endorse any party with proposals that promote budget analysis and transparency," he said.
"I think we need to hear from all parties on how they will govern in a world of significant economic uncertainty."
The Liberals have been using Page's words from last week in an attempt to contradict what the New Democrats have been touting as praise from the former watchdog for their economic policies.
"Even though Canada's former budget watchdog called the NDP’s fiscal plan 'Swiss cheese,' leader Thomas Mulcair insists Kevin Page has very nice things to say about his party's document," the Liberals said in a statement Monday.
Mulcair has promised balanced budgets in each of the next four years, and has projected a $4.1-billion surplus next year.
But critics have pointed out the NDP estimates are based on fiscal projections from the Conservatives' April budget that they say are out of date, particularly given a dramatic slide since then in world oil prices.
Mulcair said at a campaign stop in Moncton, N.B., on Tuesday that a government under his leadership would not raid surpluses in the employment insurance fund to achieve balanced budgets.
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