HALIFAX -- Nova Scotia's NDP premier sent the clearest signal yet that he's about to call an election by releasing a party platform Friday that partly focuses on cutting costs for families by promising to make things like car seats and strollers exempt from the province's harmonized sales tax.

Darrell Dexter has been careful not to show his hand on election timing, but the platform's release at a Halifax recreation centre filled with candidates and campaign workers suggests an election could be called as early as Saturday. That would likely mean voters will go to the polls on Oct. 8 in a 31-day campaign.

The party is basing its campaign on seven broad commitments that Dexter says would not cost the province more than $34.4 million annually.

"The last election was about change. The next election will be about the future," Dexter said.

"The experience of the NDP means Nova Scotians are seeing a platform that is fully costed to keep the budget balanced."

Both opposition leaders questioned the NDP's ability to maintain a balanced budget that has been forecast for the 2013-14 fiscal year when the party is promising tax cuts and increased spending.

"There's a big page missing and that's the one with all the details around the costing," said Liberal Leader Stephen McNeil.

He said with a flurry of government spending announcements over the summer and now the platform promises, the province is likely looking at a deficit for this fiscal year.

"We have very rosy revenue projections," said McNeil. "If the premier is going to make all of these the commitments then he needs to tell Nova Scotians where he's going to cut."

Progressive Conservative Leader Jamie Baillie accused Dexter of playing a political game with the release of the platform before the election is called.

"It is political game playing that really has nothing to do with what the voters want and deserve and more about the NDP trying to manipulate a political result," he said.

Baillie has promised to bring in legislation fixing election dates. Nova Scotia is the last province in the country without set election dates.

Despite the release of the platform, Dexter wouldn't say when he is going to call an election. The NDP has been in power for more than four years.

Dexter is scheduled to visit Cape Breton on Saturday, with stops in Eskasoni, New Waterford and Port Hawkesbury.

Dexter said the promise to cut the HST on goods the party describes as "family essentials" and keeping home energy bills exempt from the tax would cost an estimated $3.2 million a year. The NDP plans to make more items exempt from the HST, but Dexter said details of those would come during a campaign.

Another $18 million would be set aside annually for various programs, such as improving roads and encouraging the hiring of apprentices, he said.

The NDP holds 31 seats in the legislature, the Liberals 12 and the Tories seven. Two seats are vacant. When the election is called, it will be fought on a new electoral map that cuts the number of seats in the legislature to 51 from 52.

McNeil, 48, would be the acknowledged front-runner if there is a fall campaign. He has been the primary target of the other two parties, with the New Democrats running ads over the summer questioning whether the former small business owner has the leadership skills to be premier.

Baillie, 47, hasn't led his party into a campaign before, but the accountant and one-time president of a credit union is schooled in the province's politics having served as chief of staff to former Tory premier John Hamm a decade ago.

Dexter, 55, a lawyer, led the NDP to its first victory in Atlantic Canada in 2009. The party's win was greeted by a wave of optimism as Dexter was given a strong majority government by voters after successive Tory minorities.

The NDP's victory wasn't a fluke. The party carefully nurtured its support in urban Halifax then waited for a breakthrough under Dexter's leadership in rural parts of the province where voters might have been more suspicious of the party's labour roots and big spending reputation.

Before its historic election victory, the NDP came close to winning in 1998 and 2006. The NDP inherited a listless provincial economy in 2009 that provided immediate challenges for a party that promised fiscal prudence.

The HST has been a political lightning rod for the NDP since it came to power. The goodwill surrounding its historic election win began to evaporate in the spring of 2010 when Dexter broke a key election promise by raising the HST after a blue-ribbon panel recommended the move because of the size of the province's deficit. Before Dexter was elected, he promised to balance the books the following spring without raising taxes or cutting spending.

In 2012, the government promised to reverse the tax increase with two equal cuts in the tax rate starting next year, bringing it back to 13 per cent in 2015. The promise to reduce the HST separates the NDP and the Liberals, who have not agreed to reverse the tax increase.

The NDP is projecting a budget surplus of $18.3 million in 2013-14, but McNeil has said it wouldn't be prudent to cut the HST until he is sure a deficit can be avoided.

In the last election, Dexter committed to balance the province's books for three straight years after the NDP's first year in power, which he accomplished once in the 2010-11 fiscal year.

On Friday, Dexter promised to balance the budget for the next four years.

"As we see balance going forward that's going to empower the government to do more things," he said.

"When you faced what we faced when we came into government, which was a big deficit and really not much in the way of choices at all -- well, if there were choices they were very difficult ones -- so we have the benefit now of having returned the province to balance and therefore we can be more aggressive about things like future government programming.

The cost of the HST cut to the provincial treasury has been factored into the government's budget forecasting, Dexter said.

Part of the NDP's rosier outlook for the province is based on a federal shipbuilding program that's worth $25 billion to build the next generation of Canada's warships. Shipbuilding jobs in Halifax are expected to have a significant impact on the province's economy, as well as Nova Scotia's involvement in a $7.7-billion plan to develop the Lower Churchill hydroelectric project.

Dexter also promised in the party platform to forge ahead on Muskrat Falls, which will see the hydroelectric development in Labrador bring power to the island of Newfoundland and continue via a subsea cable to Nova Scotia.

Doubts have been cast on the project since a provincial regulator questioned whether it guarantees the lowest electricity prices for customers of Nova Scotia Power.

The Liberals and Conservatives have made energy costs a key issue, with McNeil promising to break Nova Scotia Power's monopoly. Baillie has come out with a plan to freeze power rates for five years.