The introduction of the HST has been met with protests across Ontario. (CBC)

Ontario's controversial move to harmonize sales taxes will be part of a new $1.6-million government ad campaign that's poised to hit newsstands on Thursday.

The print ads, which highlight an income tax cut that took effect Jan. 1, will invite readers to "take a closer look at Ontario's new tax package" by visiting a government website.

More than 400,000 people have visited the website, which will help residents figure out how the tax changes will affect them and their businesses, Revenue Minister John Wilkinson said Monday in announcing the campaign.

"This is the largest tax reform in over 40 years," he said during a Liberal caucus retreat in downtown Ottawa.

"So it's really important for people to make sure that there's a source of information that they can go to get the facts."

There is "misinformation out there" about harmonizing the eight per cent provincial sales tax with the five per cent federal GST next July, Wilkinson added.

Ontario's opposition parties are bitterly opposed to the HST, saying it will hurt people who are already struggling during the economic downturn.

Tax harmonization will increase the cost of many items that were previously exempt from the provincial levy, from gasoline to internet bills, haircuts and real estate fees.

Ads above board, say Liberals

Wilkinson said the ads were approved by auditor general Jim McCarter, ending months of speculation that the Liberals might opt to pay for the ads with party funds to circumvent Ontario's strict rules on government advertising.

The Liberals put the rules in place after taking office in 2003 to curb what they described as abuse of taxpayers' money on partisan ads by the previous Conservative government.

"We've been working very closely with his office to ensure that the ads meet both the intent and the spirit of the laws, and so we're very proud of them," Wilkinson said.

Apart from a magnifying glass that draws attention to the income tax cut, the ad contains little imagery or information on the tax changes that passed in the legislature in December.

"Visit ontario.ca/taxchange to see how the personal income tax changes affect you," the ad states. "And find out more about all of the tax changes including the harmonized sales tax [HST]."

There are no plans yet to expand the ad campaign to television and radio spots, Wilkinson said.

Opposition unimpressed

Progressive Conservative Lisa McLeod wasn't satisfied with Wilkinson's explanation, calling the ads another broken promise that just "adds insult to injury" by costing taxpayers more money.

"He just flip-flopped again on his promise to ban political advertising," she said.

"He is hard-wired to tax and spend, and with the HST ads, he's managing to do both."

The New Democrats echoed that frustration, arguing that all the information in the ads could have been distributed through public hearings.

"Coincidence of coincidence, [the ad campaign] starts now and it finishes one or two days after two key byelections in eastern Ontario," said NDP finance critic Michael Prue.

"He's doing it for crass and pure political reasons."

Like Ontario, British Columbia will also harmonize its PST with the GST on July 1, something New Brunswick, Nova Scotia and Newfoundland and Labrador have already done. Quebec is also considering a move towards full sales tax harmonization.

Federal Finance Minister Jim Flaherty, who has long advocated for tax harmonization, agreed to kick in $4.3 billion to Ontario and $1.6 billion to B.C. in a deal struck last year.

Much of the federal cash going to Ontario will be used to fund government cheques of up to $1,000 for families and $300 for individuals in the first year of the HST to offset the pain.