It appears two key members of Stephen Harper's inner circle don't see eye-to-eye — yet again.

This time, Finance Minister Jim Flaherty and Employment Minister Jason Kenney are clashing over a key promise Conservatives made in the last federal election en route to their majority mandate.

On Wednesday, Flaherty suggested that expanding income-splitting for families with dependents under the age of 18 may not be the ideal way to spend the "nice, clean surplus" he anticipates in time for the next election.

Flaherty's budget projects a $6.4-billion surplus in 2015. He expects it will cost roughly $2.5 billion to fulfill the income-splitting promise that was central to the Tory campaign in 2011, but told the Ottawa Chamber of Commerce he'd rather pay down public debt and cut taxes.

"There's a tendency among politicians to always — regardless of political stripe — to always want to throw baubles out the window and pretty things — 'Look over here' — you know,'' he told reporters. "And this is a shiny thing. Vote for me because I have a shiny thing. I'm not there.''

A recent report by the left-leaning Canadian Centre for Policy Alternatives found that 86 per cent of Canadian families would find nothing to be gained from the plan.

Flaherty seemed to concede as much Wednesday.

"It's an interesting idea. I'm just one voice. It benefits some parts of the Canadian population a lot. And other parts of the Canadian population virtually not at all," he told reporters.

But Kenney disagrees with the finance minister.

The employment minister told Postmedia on Wednesday that income-splitting means tax fairness for families and was a campaign pledge.

"All I know is we keep our platform commitments," Kenney said. "We made a platform commitment to introduce income-splitting when we get to a balanced budget. We'll get to a balanced budget next year, that's very clear."

Treasury Board President Tony Clement echoed those sentiments.

"I know what our campaign commitments are and I stand by those commitments," Clement said.

Maxime Bernier, minister of state for small business, seemed to side with Flaherty.

Opposition Leader Tom Mulcair pounced on Flaherty's comments Wednesday, asking Harper if he agreed that income-splitting would provide no relief to the vast majority of Canadian families.

"This government said in the last election, made a commitment, that when we balance the budget ... one of the highest priorities of this government will be tax reduction for Canadian families," Harper said.

New Democrat MP Peter Julian said Flaherty's remarks point to "incoherence" within the federal cabinet and the Prime Minister's Office.

"We now have a finance minister backtracking from what was a key Conservative commitment," he said.

But political junkies may be most interested to see Flaherty and Kenney once again taking different positions.

The two ministers have reportedly had tension simmering between them for years, even if Kenney recently called Flaherty the best finance minister on the planet.