The government is accusing its former parliamentary budget officer of partisanship and favouring opposition MPs over Conservatives.

Conservative MP Andrew Saxton said Thursday in the House of Commons that Kevin Page, who retired as Parliament's budget watchdog last month, would "routinely ignore requests from Conservative MPs to estimate the financial costs of private members' bills that were before Parliament."

But Page was ordered by the House finance committee 2011 to cost all private members' bills, and his office regularly performed that function, said assistant parliamentary budget officer Sahir Khan.

Saxton, who is Treasury Board Minister Tony Clement's parliamentary secretary, was answering a question from the NDP about a recent federal court case that reinforced the parliamentary budget officer's mandate to provide financial information to MPs about the cost of government bills. The court dismissed Page's specific bid to obtain information on behalf of NDP Leader Tom Mulcair about the costs of the 2012 budget's savings, but did back up Page's general responsibility to pursue the information.

Saxton, speaking in question period, said," We look forward to appointing a parliamentary budget officer that is non-partisan and a credible source of financial information."

It's not clear why Saxton thinks Page refused to cost private members' bills. In September 2011 the House of Commons finance committee passed a motion that the "the PBO automatically always provide the committee, within 45 calendar days of a private member's [bill] ... a detailed and comprehensive costing analysis of all such items."

In October 2011, in a letter from Page to the chair of the finance committee, Conservative MP James Rajotte, the budget watchdog says the motion "to cost PMBs [private members' bills] is a welcome reaffirmation of one of the limbs of the PBO's legislative mandate." In the letter, posted on the PBO's website, Page continues, " I would greatly value the opportunity to discuss the operational parameters surrounding the request."

Page's position was created by the Conservative government as part of its Federal Accountability Act when it first took office in 2006. However, during his five-year term, Page's probes into the costs of proposed government bills seemed to irritate the cabinet, and Finance Minister Jim Flaherty often accused him of exceeding his mandate.

Liberal MP Scott Brison, a member of the finance committee, said, in a telephone interview Thursday, it was the Conservative majority on the committee that forced Page to cost private members' bills, even though Brison said Page's job was to analyze the costs of government spending, procurement and cuts. Brison said that Page barely had the resources to do that job and, "This was an effort to put a fire hose in his mouth at a time when he was drowning."

Nevertheless, Brison said, Page managed to cost many private members' bills, including ones about:

Discovering Canada.

A tax credit for volunteers.

Parental leave for multiple births and adoptions.

Income averaging for artists.

Removal of the CPP clawback for Canadian forces and the RCMP.

Asked by CBC News to provide examples of Page refusing to cost a Conservative MP's private member's bill, Clement's office pointed to a reference in a May 18, 2009, Hill Times article about Conservative MP Jeff Watson having asked for a cost comparison of cap and trade versus carbon tax, and being turned down because the PBO didn't have the resources to carry out his request.