FREDERICTON -- New Brunswick's Liberal party is taking direct aim at the New Democrats as the provincial election campaign enters its final week, raising questions about why the perceived front-runner would be concerned with a party that hasn't held a seat in the legislature for almost nine years.

Liberal Leader Brian Gallant took aim at the NDP platform Monday, saying it doesn't contain cost estimates for 24 of its main commitments.

"There's a lack of transparency when it comes to the costing," Gallant said in an interview. "Frankly, we believe they are playing with the emotions of New Brunswickers."

Gallant also took issue with NDP Leader Dominic Cardy's criticism of the Liberal plan to spend $900 million to improve infrastructure.

"We've seen Mr. Cardy during the campaign say that if we're going to attract business, we have to have the highest quality infrastructure," Gallant said. "Yet he spent the whole campaign criticizing our plan to invest in our roads and our infrastructure to create jobs and foster economic development."

Gallant's focus on the NDP marks a recent shift in a campaign where the Liberals have largely set their sights on the governing Progressive Conservatives. On Friday, the Liberals sent a news release accusing the NDP of having candidates parachuted into ridings where they are not actively campaigning.

Cardy said he believes the attacks are a sign that there is trouble within the Liberal camp.

"They appear to be desperate," he said. "It appears the wheels are coming off the Liberal bus."

Geoff Martin, a political scientist at Mount Allison University in Sackville, N.B., said the Liberals may be going on the attack because the NDP could play the role of spoiler in some close races with the Progressive Conservatives in next Monday's vote.

"If too many Liberal votes bleed away to the NDP, then there's a concern about the Conservatives winning close races," Martin said.

"The Dominic Cardy-led NDP I think is trying to appeal to the general voter, the centre or centre-Conservative voter, and that's kind of a territory that Brian Gallant and the Liberals want for themselves."

Political scientist Tom Bateman of the University of New Brunswick in Fredericton said the Liberals may have peaked too early in the polls and party officials may be telling Gallant to launch an offensive in the final days.

"What he might be doing is taking the advice from his people to the effect that he has got to have a good offence as his best defence against a slide away going into the election," Bateman said.

Bateman said he doesn't see the New Democrats winning seats but the party could split the vote in some ridings.

"The NDP could poll 10 or 15 per cent, which is a lot better than they've been doing in recent elections," he said.

"The question is, 'From whom will those votes come? Will they come from Tory voters or will they come from Liberal voters?"'

Gallant defended his critique of the NDP platform, saying he has an obligation to tell voters what he thinks of it.