OTTAWA - Only one week before they expect to be plunged into a federal election campaign, some Liberal MPs are still hoping to make "adjustments" to the centrepiece of their party's platform -- the risky proposal to impose a carbon tax.

They want Liberal Leader Stephane Dion to massage the so-called green shift to make it more palatable to farmers, truckers, rural residents and others who stand to be hardest hit by a tax on fossil fuels and who have not yet been appeased by the promise of offsetting income tax cuts and tax benefits.

Having spent the summer consulting with Canadians about the green shift, Liberal agriculture critic Wayne Easter said Dion and his MPs must now decide how to respond to some of the concerns that have been raised.

"We need to boil that down, we need to figure what changes have to be made to accommodate the concerns that are raised," Easter said in an interview.

"And there are concerns. We don't deny that."

The fact that some MPs are still hoping for last-minute changes to make the green shift more marketable is just one sign the Liberal party may not be firing on all cylinders by the end of next week, when Prime Minister Stephen Harper is virtually certain to pull the plug on his government.

Some Liberal insiders complain that continued infighting among factions in Quebec has turned that province into "a disaster zone" -- as one well-connected Grit called it -- for the party.

They also grumble that key national and regional campaign posts are only now being filled and that many veteran, experienced organizers have been left sitting on the sidelines.

Liberal MPs and senators are scheduled to meet Tuesday through Thursday in Winnipeg. The summer-ending caucus retreat had been intended to plot strategy for Parliament's return on Sept. 15, but caucus chairman Anthony Rota said the meeting will now focus exclusively on election preparation and strategy.

But even with an election looming, Easter said caucus still needs to discuss the green shift adjustments that constituents have told MPs are necessary.

"There's been positive feedback but there's also been some adjustments that need to be made and we really need to sit down and talk about that and put our best foot forward," Easter said.

When Dion launched the green shift last June, he said Liberals would spend the summer having a "dialogue" with Canadians about the complicated plan. Since then, one insider said the leader has rejected any criticism of the plan, insisting "there will be no changes, not a comma."'

However, Easter and other MPs clearly remain under the impression that the plan can and will be fine-tuned.

Robert Thibault, a Nova Scotia MP, said the purpose of the summer consultations was to determine "what are the adjustments that have to happen, not to assume we got it all 100 per cent, completely right."

While Dion has touted the green shift as a comprehensive, detailed plan to combat climate change, Thibault said: "In my mind, it's a statement of principles, it's not a recipe."

Unlike Easter, who would like changes made before the election is called, Thibault said he thinks voters will accept that they won't get all the details until the plan is actually implemented.

"I think if we talk to people (and tell them) this is a statement of principles, of intent . . . and during the implementation that there's leeway to discuss with Canadians, I think that's the logical way to do it."

Mark Marissen, national co-chair of the Liberal campaign, said there's no plan to change the green shift. However, he said there will be other environmental proposals in the platform that may supplement the green shift and answer some of the concerns that have been raised.

Marissen also insisted that the party is ready to bolt out of the starting blocks the moment the election is called.

"We are ready on every front," he said.

Some veteran Liberals disagree, especially when it comes to Quebec where some Liberals remain furious with Dion's Quebec lieutenant, Senator Celine Hervieux-Payette. They blame her for failing to find candidates for half the ridings in the province while blocking potentially strong candidates, such as former MPs Liza Frulla and Helene Scherrer.