The opposition New Democrats say they have documents that show a Parliament renovation contract was amended at the last minute to favour a Montreal contractor with ties to the Conservative Party.

The RCMP is investigating a multimillion-dollar contract awarded to Paul Sauvé's company to renovate Parliament's West Block. (Adrian Wyld/Canadian Press)NDP MP Pat Martin said an amendment to the $9-million contract awarded to Paul Sauvé's firm two years ago removed a clause requiring the contractor to line up subcontractors for specific work on the West Block, including iron work and copper roof repairs.

Martin told the CBC's Julie Van Dusen on Monday that the change has "all the earmarks of political intervention in the awarding of government contracts."

"It's not only wrong, but it's costing the taxpayer a fortune because we're doing everything incorrectly," Martin said outside the House of Commons. "We're going to have to do it twice."

Liberal MP Marcel Proulx said experts in the construction business have told him that the removal of the clause was a clear way of favouring Sauvé.

Questions have been swirling in recent weeks over the tendering process to repair the Parliament buildings, which began in 2007.

The controversy began after it emerged the RCMP were investigating the contract awarded to Sauvé, who owns bricklaying company LM Sauvé.

Sauvé recently told Radio-Canada he hired Gilles Varin to lobby for him so he could win the contract. Varin, a long-time Quebec Conservative supporter, was not a registered lobbyist at the time.

Paradis under pressure

The Conservative government insists that none of its members are being investigated by the RCMP and stressed it has tightened restrictions on individual donors to political parties.

During Monday's question period, the opposition parties called on the Conservatives to disclose who in the minister's office approved the amendment.

Public Works Minister Rona Ambrose replied that the government has contracting laws and policies in place and public servants are responsible for managing the projects and adhering to those regulations.

"If there is any wrongdoing by any individuals or contractors, they will face prosecution under the full extent of the law, including the Accountability Act, and taxpayer money will be recouped," Ambrose told the House.

But the opposition is already calling for the resignation of Natural Resources Minister Christian Paradis for his involvement in the project, as well as a Montreal-area Conservative riding association fundraiser in January organized by Sauvé.

Paradis previously managed the Public Works portfolio in Prime Minister Stephen Harper's cabinet, as did former Conservative senator Michael Fortier, who was minister when Sauvé was awarded the contract.

"There's a very bad odour wafting around the West Block these days and around these contracts being managed by the Conservative government," Halifax-area Liberal MP Geoff Regan said Monday.

"We have … allegations of $140,000 payoffs to unregistered lobbyists," he said. "We have government contractors going to Conservative fundraisers."

Sauvé said he threw the fundraiser at the behest of Varin and the head of the Conservative riding association in Bourassa, Gilles Prud' Homme.

The riding of Bourassa is represented by Liberal MP Denis Coderre.

With files from Julie Van Dusen