Derek Burney, the former ambassador, senior bureaucrat and Conservative man-for-all-seasons who led Harper's transition team, took the extraordinary step of publicly breaking with the prime minister on the issue.
Burney decried the move in a published interview and has asked to speak to the committee about the issue alongside (Elizabeth) Roscoe.
"I put a premium on loyalty and most people in politics do, and this is affecting one of my team members in a manner I find unfair," Burney told the newspaper.
The Conservatives now face the unnerving prospect of having a totemic figure in the party campaigning against the centrepiece of a popular Conservative prime minister's agenda.
The proposed change is contained in the Accountability Act, intended to stop the "revolving door" between government and lobbyists.
The Act also stipulates that public office holders must wait for five years after leaving government before entering the lobbying world.
Elizabeth Roscoe volunteered to help Harper with transition last January and subsequently took a job as vice-president of public affairs for the Canadian Association of Broadcasters.
Within weeks of his election the prime minister brought in rules that retroactively outlaw members of the transition team from lobbying for five years.
Ain't that a crying shame. Ms. Roscoe knew that the rules were changing; while doing so retroactively is a bit unfair, it's a perfectly valid legal and political decision to make.
Somehow the sight of starving lobbyists with their begging bowls doesn't move the public to sympathize with their plight.
Source: Ottawa Citizen