The winner of the yesterday's close byelection in Victoria says it was concerns about pipelines and the environment — not a sewage treatment plant — that won the seat for the NDP.

NDP candidate Murray Rankin managed to fight off a strong challenge from the Green Party and hold on to the Victoria riding in one of three federal byelections when the final votes were counted late Monday night.

The lead between Rankin and Green candidate Donald Galloway seesawed through the night, but the final tally put the NDP ahead by just 1,151 votes.

Rankin, an environmental lawyer, says the furor over a sewage treatment plant for Victoria may have grabbed most of the pre-election headlines, but he believes other environmental concerns, such as the proposed Northern Gateway pipeline project, tipped the balance in his favour.

In his victory speech, Rankin told the crowd his number one priority will be to stop the Enbridge pipeline project.

"And we will not let this country become the energy Wal-Mart of the World."

Rankin admits the tight race against the Green party candidate was a surprise, but says it was the power of the NDP machine that pushed him over the top.

The NDP brought out all the big guns for this race.

Dozens of provincial MLAs, outgoing MP Denise Savoie, who stepped down in August due to health reasons, and even the NDP's national leader were at the Empress Hotel in Victoria last night to celebrate the victory.

"We managed to do what the NDP does so well, what Obama does so well, and that is to poll the vote. We knew who was on our side. We got them to the polls,” said Rankin.

In fact, it was the NDP's showing in the advance polls that won Rankin the seat. It was only when the final box of advanced poll ballots was counted at the end of the night that the NDP candidate surged ahead.

NDP opposition leader Thomas Mulcair was happy to have a byelection win to show his leadership has momentum.

"We know we're the only team that can stand up to Stephen Harper and replace the Conservatives in 2015," Mulcair told the crowd.

Sewage dominated campaign

The campaign itself was dominated by debate over whether to treat Victoria's sewage, with Rankin being the only candidate in support of the new plant.

The NDP's Murray Rankin said voter concern over pipelines and not a sewage treatment plant was the key to his victory on Monday. (CBC)

However, Rankin said the results show the sewage plant was not the key issue for voters.

"Sewage was not an issue nearly to the extent of the kind of environmental issues I spoke about in my speech: climate change, Enbridge, lack of action on clean environment, gutting our environmental laws,” he said.

“Over and over again, that's what I heard on the doorstep. And I think the results speak for themselves. Those who championed those other issues, such as sewage, did not fare as well in our vote.”

Green Party Leader Elizabeth May agreed with Rankin.

"The one thing I wish could have been done differently, and Murray made this point too, that this should have not been a byelection as a referendum on sewage. It was turned into that by local Victoria media in response to the Liberal candidate deciding he wanted to run on one issue and that was it," said May.

"If we had one more week because of the momentum we had getting behind us, we would have won."

Meanwhile, Capital Regional District directors are expected to vote on whether to ask to extend the federal government's deadline for treating sewage at a special meeting later Tuesday morning.

The other two byelection in Calgary-Centre and Durham Ontario were both won by the Conservatives.

With files from The Canadian Press