OTTAWA - Air travellers are facing an April Fool's Day surprise that's no joke.

The federal government is set to raise the airport security tax on April 1 -- subject to parliamentary approval -- to cover the cost of full-body screening and other new security measures.

Transport Minister John Baird announced Thursday that the government will put up $1.5 billion over the next five years to tighten security.

To cover that, air security fees will rise by $2.50 for a one-way flight in Canada, by $4.37 for transborder flights, and by $8.91 for international routes. The fees currently range from $5 to $16 a ticket, depending on the destination.

Baird played down the increase, saying it's not much more than the cost of an in-flight pillow or a headset.

The announcement came after the government said next week's budget wouldn't raise taxes. Baird said the security charge is a user fee, not a tax.

NDP deputy leader Thomas Mulcair begged to differ.

"A tax is a tax is a tax," he said in an interview. "They're trying to jazz it up as something other than what it is. It's a simple tax."

Mulcair said the measure comes at a bad time for struggling companies.

"The government's making it harder and harder for the airlines and the tourism industries to do business."

The Liberals also criticized the Tories for raising the tax, especially while Parliament was on a break.

The government announced recently that it will spend $11 million to install 44 airport scanners that can see through travellers' clothes.

And the Canadian Air Transport Security Authority -- the federal agency responsible for keeping air travel safe -- is bringing in a new behavioural observation program to look for suspicious travellers. It will spend millions to train people in the techniques.

Baird also announced a full review into the security agency itself. The study will look at CATSA's spending, efficiency and structure.

Baird blamed the failed Christmas terror plot on a U.S.-bound airliner for increased security needs.

"The terrorist attack that took place just two months ago today was a stark reminder for governments to remain vigilant about aviation security.

"Our government is unwavering in our determination to keep all Canadians safe and secure from terrorism, and we are taking the necessary measures to meet this goal."

It is a good time to introduce the increase now that there is evidence the economy is improving and Air Canada, Westjet and Porter are all in better positions than they were a year ago, Baird said.

Norm Payne, senior consultant for Uniglobe Travel, predicted travellers would soon tire of the hikes.

"People's patience to pay taxes is just like the runway, at some point, it ends," he said.

"If you take a flight from here to London tonight, the price of the ticket is $764. The taxes are $394. If you add another eight or 10 dollars for the CATSA tax, that means the tax is half the price of the ticket."

"People don't like paying extra taxes. It's pretty simple."

Mulcair welcomed the review of CATSA, saying current funds are being squandered.

"There's more than enough money there, if well spent, to provide security for the travelling public."