QUEBEC — An independent Quebec would be swimming in billions of dollars in extra cash, says a Parti Quebecois study that one opponent immediately dismissed Thursday as an "Alice in Wonderland" scenario.

Parti Quebecois Leader Bernard Landry said sovereignty would lead to Quebec having its own version of the massive surpluses posted in recent years by the federal government.

The extra cash would come from Quebec taking over federal taxing powers and reducing duplication in government services, says the plan, which was drafted by PQ finance critic Francois Legault.

Legault estimates an independent Quebec would have $1.3 billion in extra money in 2005-06, an amount that would grow steadily each year to reach $4.5 billion in 2010.

Over a five-year period, the total would be $13.8 billion.

"For most people, the decision to support sovereignty is a combination of the heart and reason," Landry told reporters after the plan was unveiled.

"Some people by nature have material worries. We are addressing those material worries. A sovereign Quebec would be in a much better situation than the province of Quebec."

PQ opponents quickly pointed out the study is based on a host of rosy predictions, including easy negotiations with the rest of Canada and a docile reaction from financial markets.

"It's Alice in Wonderland, pure optimism," said Finance Minister Michel Audet.

"It puts all assumptions on the side of optimism, whether on revenue or expenditure side. It does not make sense to present that as a realistic view of the future."

Audet said Quebecers have received more money from the federal government than they have sent to Ottawa for more than a decade.

But Audet said that doesn't mean the federal government shouldn't be giving all provinces more money from its huge surpluses to correct what Quebec calls a "fiscal imbalance."

He said the PQ plan ignores transitional costs and the financial shock that independence would cause.

After assuming its share of the massive Canadian debt, Quebec would be one of the most heavily indebted countries in the world, Audet said.

Quebec's own debt is close to $120 billion.

The PQ plan assumes Canada would agree to many of the optimistic assumptions.

"Nothing is going to be easy if Quebec breaks up Canada," said Quebec Intergovernmental Affairs Minister Benoit Pelletier.

"Maybe we could call it Legault in Dreamland."

The financial forecast uses simple calculations to establish Quebec's spending in areas currently run by the federal government. The PQ calculates that Quebec's share of the national debt would be 18 per cent even though the province forms 23 per cent of the Canadian population.

Mario Dumont, leader of the Action democratique du Quebec, said the PQ politicians appear to be seeing the future through rose-coloured glasses.

"If you take all the best scenarios, you end up with a gain," said Dumont, who was on the sovereigntist side in the 1995 referendum.

"But I think we all know life doesn't work that way."

The report says Quebec would retain all federal employees while somehow cutting billions in overlapping expenses.

Landry and Legault will have to be patient because Premier Jean Charest doesn't have to hold an election until the spring of 2008.

And even if the PQ wins the election, it is unclear how quickly a sovereignty vote would take place as PQ premiers in recent years have taken to pushing back their plans for a sovereignty referendum.

Legault's study was released a month before Landry faces a confidence vote on his leadership. Legault is considered a potential leadership rival.

The study carefully avoids the word "surplus," referring instead to "room to manoeuvre" to describe the extra billions of dollars.

The money would not necessarily translate into a surplus because Quebecers would still have to decide whether to spend it on a variety of new responsibilities, like buying new military equipment or setting up foreign missions.