The Liberal party's national campaign co-chair has stepped down after it was revealed that he sent an email to several people behind the Energy East pipeline, advising them how to lobby a new government.

In an email, Dan Gagnier told five people at TransCanada Corp. to target the right people in a new government as quickly as possible so they can help shape national energy strategy decisions, if the Conservatives lose the election next week.

Gagnier wrote that such lobbying will be necessary to ensure timelines for projects like the Energy East pipeline aren't put at risk.

"If there were ever a time for energy companies to act with clarity and uniformly, it would in a change of government scenario," Gagnier allegedly wrote.

In a statement released Wednesday evening, Gagnier said he had relinquished his role to "avoid becoming a distraction."

"I deeply regret that the campaign has been affected by these negative personal attacks," wrote Gagnier. "I have always conducted my business openly and in full accordance with the rules."

Both the Conservative and the NDP campaigns criticized the letter Wednesday, suggesting the Liberals are trying to influence contacts and friends in the oil and gas industry.

NDP candidate Alexandre Boulerice sent a letter to Karen Shepherd, the commissioner of lobbying, requesting an investigation.

"These allegations are precisely the kind of backroom dealing that undermines Canadians' trust in their democracy, and causes them to believe that it's Ottawa-insiders, not ordinary citizens, who shape the decisions of government," wrote Boulerice.

NDP candidate Charlie Angus also condemned Gagnier's alleged actions in a news release earlier on Wednesday.

"It just goes to show that the ‘real change’ Mr. Trudeau is offering is apparently to replace the Conservative ‘old boys club’, with the Liberal ‘old boys club,’” NDP candidate Charlie Angus said in a news release.”

Conservative candidate Paul Calandra also had harsh words for Justin Trudeau and the Liberal party in light of the controversial email.

"Justin Trudeau doesn't represent change, he represents the same old Liberal Party that brought you the sponsorship scandal," said Calandra in a statement.

"(It is) a party run by elite insiders who sell their influence to the highest bidder to the detriment of taxpayers."

A statement from the Liberal party said Gagnier made his decision "in the best interest of the party" and he has "always operated within full accordance of the rules."

Earlier Wednesday, a Liberal spokesperson told CP that Gagnier's email has "nothing to do with his volunteer role on the campaign." She also said that Gagnier didn’t advise Trudeau on energy issues.