Prime Minister Stephen Harper walks with local MP Tony Clement in Huntsville, Ont. in June, during a tour of the G8 summit site. (Adrian Wyld/Canadian Press)

The cost of hosting the G8 and G20 summits next month in Ontario now stands at $1.1 billion and further outlays are likely, federal documents show.

The price tag includes $160 million for hospitality, infrastructure, food safety and extra staffing. That amount is in addition to the $933-million security bill the Tories revealed earlier this week.

Protesters confront police in London in April 2009 as thousands of demonstrators converged on the centre of the city to protest against the G20 summit. (Owen Humphreys/Associated Press)

"This might be the most expensive 72 hours in Canadian history," Liberal MP Mark Holland said.

But Public Safety Minister Vic Toews defended the costs for security, saying Canada has an obligation to make sure world leaders are safe while visiting Toronto and Huntsville, Ont.

Liberal Leader Michael Ignatieff blamed the Conservative government's "poor management" for the ballooning cost estimates.

Ignatieff said Wednesday that Canadians can't understand how the government's initial earmarking of $179 million for security has multiplied in the space of a couple months.

"These numbers are off the scale with other G8s and G20s," Ignatieff told reporters outside his party's weekly caucus meeting in Ottawa.

"We're three weeks away from the event where Canada will be on the world stage, and I want to be proud of Canada. For now, I'm embarrassed."

Not a cost overrun: Toews

In an interview with CBC News earlier in the day, Toews defended the security estimate as the "most efficient and effective" use of public money for Canada's "unprecedented" hosting of back-to-back international summits. He also insisted the estimate was not a cost overrun.

"This has been budgeted for, and the money is released as it is required," Toews said.

The estimated cost for security over the course of seven days in June dwarfs the amount spent at previous international summits and is expected to surpass the $898 million spent during the Vancouver Olympics — which spanned 14 days.

The official price tag for security at last year's G20 summit in Pittsburgh was listed at $18 million US, according to municipal and U.S. federal officials.

But Toews said comparing the costs for security at this year's summits with the amount spent at the Olympics is like comparing "apples and oranges" because the G8 and G20 meetings, with so many heads of countries visiting at once, require a very "different type" of security.

"Granted there were some heads of nations at the Olympics, but nowhere in the configuration or the numbers that are going to be here," Toews said. "I don't think you can say, 'Well, because it's seven days instead of 14 days, it should be half the price.' It simply doesn't work that way."

The face-to-face meetings, Toews said, allow leaders to deal with issues that simply can't be handled over the phone or by video-conference.

When asked by the Liberals during Wednesday's question period to explain the costs, Toews said the government believes the experts when they say such a level of security is necessary.

"I understand that the Liberals don't believe in securing Canadians or the visitors here," Toews told the House. "We're different."

NDP Leader Jack Layton said the Conservatives have "quadrupled" funding for security, and some of that money could have gone to the government's G8 maternal health initiative. Layton then chastised the Conservatives for refusing to include abortion in its maternal health plan.

"You can do a lot of things with a billion dollars," Layton told the House.

In response, Prime Minister Stephen Harper repeated the government's position that Canadians do not want a debate on this matter.

Single venue would have saved money: Liberals

G8 leaders will gather in Huntsville, Ont., late next month, then join other world leaders for the G20 summit in the heart of downtown Toronto. The security money will be used for planning, accommodation, information technology and working with security partners to protect leaders and their delegations.

The additional $160 million in costs includes about $100 million for office and meeting spaces and pre-summit meetings. Another $1.2 million is to ensure the food served to dignitaries is safe and healthy, while $10 million has been spent on infrastructure and about $50 million has been paid to spruce up the Huntsville area.

Ignatieff ridiculed the Conservatives for switching the G20 meeting venue from Huntsville to Toronto months into the planning stage.

"At first they said Huntsville, then they said, 'Oops, Huntsville is too small and too many flies. Let's high-tail it down to Toronto,'" he said. "This is the confusion we're talking about."

Holland said the government could have reduced security by hosting both summits at a single location, instead of the "logistical nightmare" of two separate venues hundreds of kilometres apart. But Toews said the dates of the summits were actually moved closer together to save money.

Holland said security for the summits is critical, but the government shouldn't be handed a blank cheque.

"We're not talking about cutting corners; we're talking about proper planning," Holland told CBC News on Wednesday. "They tried to force a round peg into a square hole."

Security plans for the G20 meeting in Toronto feature two fenced areas — an outside fence that will close off a large section of the downtown and disrupt access to homes and workplaces, and an inner fence that will control access to hotels and the convention centre.

Later Wednesday, Chris McCluskey, a spokesman for Toews, accused Ignatieff of failing to understand the cost of the summits.

"His comments indicate he has no understanding of the parliamentary budget process, no understanding of the reality of providing security to world leaders, and no understanding of what it takes to have Canada take its rightful place on the world stage," he said in an email.

"The only embarrassment here is Mr. Ignatieff’s ill-informed commentary on an event he should be supporting."

With files from The Canadian Press