OTTAWA - Canada's inflation rate resumed its upward trajectory last month, ramping up pressure on the Bank of Canada to begin raising interest rates in a little over a week's time.

Statistics Canada said Friday that the annual inflation rate jumped a bigger-than-expected four-tenths of a point to 1.8 per cent in April, mostly due to base effects from higher gasoline prices.

On a month-to-month basis, Canadians paid 0.3 per cent more for consumer goods in April than they had in March.

But the more concerning figure, at least to the Bank of Canada, is that underlying core inflation also rose sharply by 0.3 per cent from March and to 1.9 per cent on an annual basis.

The consensus of economists was for the overall index to rise to 1.7 per cent and core, which excludes energy, to 1.8 per cent in the month.

The Bank of Canada was widely expected to bring an end to its extremely stimulative low interest rate policy when it next sets rates June 1. The quarter point trendsetting overnight rate had been in effect for over a year, but volatile market reaction to the expanding European debt crisis in recent weeks added an element of doubt to the view.

Now analysts say bank governor Mark Carney could go either way, which is why April's inflation numbers, the last he'll see before the rate decision are regarded as key.

While both core and overall prices remain below the bank's two-per-cent target, the underlying inflationary pressures have been considered surprisingly strong in an economy that is still operating significantly below capacity.

This week, the United States reported that prices there are moving lower in that country.

April inflation in Canada was heavily influenced by base effects of low energy prices a year ago, when the economy was still in a deep recession. Gasoline prices were up 16.3 per cent in April from a year earlier, and natural gas was 3.3 per cent higher, when in March natural gas had been 22.4 per cent lower from a year earlier.

"Overall, energy prices rose 9.8 per cent between April 2009 and April 2010, following a 5.8 per cent increase during the 12-month period to March," the agency said.

"Excluding energy, the consumer price index rose 1.1 per cent."

Other significant increases came in the cost of purchasing a car, which cost 5.3 per cent more in April from a year earlier, while food prices were relatively tame registering a one per cent increase.

In the core index, which excludes energy, the agency said the increase was due to higher prices for vehicles, car insurance, property taxes and restaurant meals.

Regionally, the agency said price pressure was highest in the four Atlantic provinces.