CALGARY - Dressed up as a cowboy, Prime Minister Stephen Harper blasted away at the Opposition Liberals Sunday night and promised more action to his government's law and order agenda.

Freshly home from the G8 leaders meeting in Japan, Harper celebrated his third Calgary Stampede as prime minister Sunday among more than 800 party faithful and senior government members at his Calgary Southwest riding annual barbecue.

The prime minister told the crowd that his minority government intends to deal with the "escalating problem of violent youth crime" when Parliament resumes in the fall.

"We must send a message - and we will - that we hold young lawbreakers responsible for their behaviour. That is what we intend to do this coming session."

Recent Statistics Canada figures show that while overall youth crime is down significantly in the past 15 years, youth violent crime has surged 30 per cent since 1991.

Harper received a hero's welcome from the cowboy hat-clad crowd, and he wasted no time criticizing the Opposition Liberals for trying to stand in the way of nearly each of his government's policies.

But he saved some of his sharpest attacks for Liberal leader Stephane Dion's new "Green Shift" environmental plan, saying the proposals would devastate the economy.

Harper reiterated Conservative criticisms that the Liberal plan would simply shift tax dollars out of Canadians' pockets back into federal government coffers, boosting the cost of just about everything.

"It will stop the economic progress of the Canadian middle class dead in its tracks and it will make the cost of living unbearable for fixed income seniors and low-income seniors."

Harper said the Liberal plan doesn't even set a target for emissions reductions.

"Why? Because Dion's carbon tax is not an environmental policy. It is just a wealth redistribution program disguised as an environmental policy."

Harper finished his speech by saying he has never felt more hopeful about his party, having broken the Liberal lock on power and demonstrated that there's a better way to govern Canada.

But he warned supporters that his Conservative minority government could face another election "at any time."