The B.C. Liberals are using a travelling attack ad to troll NDP leader John Horgan at campaign stops, but political scientists warn the aggressive tactic could backfire.

On Tuesday, a truck plastered with Horgan's face and the words "Say Anything John" showed up at an NDP event in North Delta, where a Liberal staffer parked it directly behind the NDP’s campaign bus.

Horgan laughed off the strategy while speaking with reporters at the stop.

"If the B.C. Liberals want to hire people to drive around in a truck following me, at least they gave someone a job," Horgan said.

The truck, like any attack ad, could do some damage, however. It attempts to paint Horgan as hypocritical for both condemning big money in politics and trying to solicit massive donations for the NDP's campaign.

Liberal staffer Shane Mills, who drove the so-called "truth truck" to Tuesday's event, described Horgan's stance as "one of the biggest things of hypocrisy I've ever seen."

The NDP has repeatedly tried to pass legislation to curb corporate and union donations in the province, to no avail, and Horgan has promised to finish the job if elected next month.

Hamish Telford, political science professor at the University of the Fraser Valley, argued the NDP leader's position is reasonable.

"Every party is entitled to fundraise according to the rules that have been set out, but also say that they want to change the rules," Telford said.

Beyond that, Telford warned that the Liberals' attempt at trolling could blow up in their faces.

"These sorts of tactics appeal to partisan activists, but others may find it a bit juvenile at best, and maybe off-putting," he said. "That's the risk they're taking."

Liberal leader Christy Clark brushed off questions about the negative message this week, directing reporters to speak with individual staffers about the "truth truck."

"I'm not here to talk about what the opposition is doing today," Clark said at a campaign stop of her own Tuesday.

Party leaders often take the high road in public and use surrogates to get into the muck on the campaign trail, Telford said, but at the end of the day, they do steer the message.

"The leaders are overall in charge of the campaign – they're setting the tone and issuing instructions behind the scenes – and if a leader doesn't like what activists are doing, he or she will put a stop to it," Telford said.

With files from CTV Vancouver's Bhinder Sajan