TORONTO—The federal government spent an estimated $3.4 million telling Canadians about the carbon tax rebate they could claim on their taxes this year.

According to a spokesperson for the Canada Revenue Agency, the cash covered a direct mail-out and a digital, radio and print ad campaign.

The campaign was targeted solely to people living in Saskatchewan, Manitoba, Ontario, and New Brunswick — provinces where the federal carbon tax was applied starting April 1.

In an emailed statement, press secretary Emilie Gagnon said the awareness campaign was launched to ensure Canadians “receive the credits and benefits to which they are entitled” which starts with making sure people are aware of them.

[READ MORE: Ontario won’t reveal price of anti-carbon tax ads]

The cost first reported by CTV this week was based on an order paper question in the House of Commons that specifically asked about the price for sending the flyers to households in the four effected provinces.

That part came to just over $1 million, but the extra costs weren’t asked for and so weren’t reported to the House.

On top of the $1,016,345.74 paid for the mail-outs, the government says an estimated $2,310,000 was spent on an ad campaign and another $90,000 was spent on research and post-campaign evaluation, according to Gagnon.

The government said the final invoices for the ads and post-campaign evaluation are still being calculated, so the figures provided are the planned expenses. The ad campaign ran for 10 weeks from Feb. 18 to April 30.

Ottawa is pointing to the 97 per cent uptake on the credit, from tax filers, as proof the awareness campaign worked.

The mailouts were tailored to each province and in Ontario trumpeted the $307 that a family of four could receive from the so-called “Climate Action Incentive payment.”

Federal Environment Minister Catherine McKenna’s spokesperson, Sabrina Kim, called the uptake “encouraging” and slammed federal and provincial conservatives for “efforts to fool Canadians about our plan with misleading flyers, stickers and partisan advertisements reminiscent of the Harper government.”

But spending millions to remind Canadians about the rebate doesn’t sit well with the federal Tories.

“Only the Liberals would spend millions of taxpayer dollars to tell Canadians about a new tax,” Andrew Scheer’s spokesperson Brock Harrison said in an emailed statement.

“The reality is that the carbon tax is not as advertised. The Liberals have exempted big polluters and still haven’t come clean on how much it will cost Canadian families in higher costs for things like gasoline and groceries,” he added.

Canada’s parliamentary budget officer has confirmed the Liberals’ assertions that the majority of households will receive more cash back from the government than what they will pay in extra costs associated with the carbon tax. Eight in ten households will be better off according to the PBO, because the tax is revenue neutral.

[READ MORE: Carbon price revenues to hit $2.6B in 2019-2020: PBO]

Using tax dollars to tell Canadians about tax savings is not a new tactic for federal governments.

In the 2010-11 budget year, for example, the Conservatives spent just over $6 million reminding taxpayers about a slew of tax credits for everything from first-time home buyers to public transit users, according to the annual report on government advertising. That price tag covered a digital, TV and print ad campaign.

Since coming to power, federal documents show the Liberals have spent millions less than the previous Conservative government on advertising.

In April, Ontario Premier Doug Ford’s government launched a taxpayer-funded ad campaign against the federal carbon tax. So far the province has refused to disclose the cost of the ad campaign, which was rolled out on radio, TV and on social media websites. However, provincial Treasury Board President Peter Bethlenfalvy told reporters in April that the Ford government is spending less than the the Trudeau Liberals on the ad campaign.

The province did not answer a request to clarify whether that was still the case, now that the cost for the federal government’s campaign are public.

Instead a spokesperson for Bethlenfalvy said the province will be “fully transparent with costs as they become finalized.”

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