VANCOUVER (NEWS1130) – The House of Commons may be out for the summer, but the mud-slinging between the Tories and the NDP is ramping up anyway.

Late last month, the Conservatives unveiled their first attack ad against new New Democrat boss, Tom Mulcair; now the NDP is responding in kind.

“Stephen Harper says the economy is very fragile… and he’s right,” the ad states. “Because after leading Canada into the worst recession of this generation, Conservatives have another economic downturn on their hands.”

It used to be that attack ads were rare between elections, but the Tories have been using them extensively to define their opponents.

One expert says it looks like the NDP is learning from the mistakes made by the Liberals.

“They thought, ‘Oh yeah, it’s a gentleman’s agreement. We’ll all agree to have our fights in the spending period, run up to election, election time’ and then the Tories broke those rules, and said, ‘We’ve got deep pockets, we’ve got lots of money to spend, and we are going to campaign all the time,’” explains Political Scientist Dennis Pilon of York University.

Pilon notes both this NDP ad and the Tory ad before it are policy-focused, a shift from the deeply personal spots the Conservatives have used in the past.