TORONTO - The cheque is in the mail.

Revenue Canada will mail HST rebates to 6.6 million Ontario residents this week, even though the 13 per cent sales tax doesn't take effect until July 1.

The rebates -- the opposition parties call them bribes -- are to help families deal with the impact of the HST in its first year. About 17 per cent of consumer purchases, including gasoline and home heating fuel, will rise by eight per cent because they are currently exempt from Ontario's provincial sales tax.

"That's money that we're passing on directly to our families from the federal government to help them cope with the introduction of the HST," Premier Dalton McGuinty said Tuesday.

Ontario couples with combined incomes under $160,000 will be eligible for HST rebates totalling $1,000, while singles earning under $80,000 will qualify for $300.

British Columbia will also switch to the HST on July 1, but unlike Ontario, isn't offering rebates to offset the impact of the new tax.

"We made a different choice than the one they made in B.C.," said McGuinty. "We decided to take the $4 billion the federal government is giving to the government of Ontario and pass that directly through to the people of Ontario to help them manage under the HST."

However, the Progressive Conservatives accused McGuinty of trying to bribe taxpayers with their own money and predicted it would backfire on the Liberal government.

"I think it's going to be a reminder to taxpayers about how big a haul Dalton McGuinty is going to take out of communities across our province with the HST tax grab," said Opposition Leader Tim Hudak.

The New Democrats insist Ontarians can't afford the HST, and said people won't be fooled by rebate cheques that end after one year when the know the tax is forever.

"It's a shell game with our own money and it's a way to bribe people with our own dollars, pretending that somehow this is going to reduce the impact of the HST, and I don't think people will buy it," said NDP Leader Andrea Horwath.

"I think people see through this kind of tactic."

The HST rebates will be sent in three instalments -- or directly deposited into your account, depending on how you get your income tax refund -- with the next payments in December and June 2011.

McGuinty and the Liberals roundly condemned the previous Conservative government for sending out $200 rebate cheques prior to the 2003 election, but Hudak said that was different from the HST cheques the Liberals are sending out.

"When the PC government sent cheques out it was because we had a surplus that year, people had paid more money than was required to meet the fiscal plan so they were refunded that amount," said Hudak.

"Let's be clear about what Dalton McGuinty is doing: these are bribe cheques that disappear after the next election. The bribe cheques are short term; his HST tax hike he intends to be permanent."

A Finance Ministry study released Tuesday showed the HST will benefit lower-income families, be essentially a wash for middle-income earners and will require the wealthy to pay more.

The opposition parties dismissed the report, saying the Liberals assumed businesses would pass along 90 per cent of their savings from the tax change to consumers in the form of lower prices.

"The government has torqued the numbers in this report significantly," said Horwath. "If numbers like this were peddled on Wall Street, somebody would end up in jail."