The national pump price average registered $1.28 per litre on Wednesday. (CBC)

The Canadian Taxpayers Federation, as part of its annual Gas Tax Honesty Day, will be paying the tax on drivers' fuel at some filling stations across the country Wednesday.

The advocacy group, which focuses on lowering taxes and making government accountable, says the federal government is slated to collect $5 billion in direct gas and diesel taxes.

CTF director John Williamson is calling on the government to lower the federal tax on gas by five cents a litre.

"Over the past 12 months — the period of May 2007 to April 2008 — the average national price of a litre of gasoline paid by Canadian motorists was approximately $1.16," the group said in a release.

"This represents a 17-cent increase over last year’s average price. Today, gasoline taxes account for an average 28 per cent of the pump price."

But critics note that a modest tax reduction won't help consumers much in the long run.

"What that would mean of course is that the gas prices that are now $1.25 a litre would come down to $1.20 — it's really not going to change anyone's life," said CBC News business commentator Michael Hlinka.

CTF Manitoba spokesman Colin Craig says Ottawa should direct all of the revenues it collects from gas taxes into road infrastructure.

"Gas taxes are high right now," he said. "The federal government has not invested that money back into roads substantially — it's only 37 per cent right now. So what we're saying is, if they're not going to use it for roads, then they should give that money back to motorists."

On Wednesday, the national pump price average registered $1.28 per litre, according to the gas monitoring website Gasbuddy.com. In the United States, the average price of a U.S. gallon climbed to $3.77.