VANCOUVER -- British Columbia's two leading political parties targeted voters' wallets with duelling promises on bridge tolls, tax cuts and rate freezes on the eve of a provincial election campaign.

Liberal Leader Christy Clark unveiled her party's platform on Monday, pledging $157 million in new spending over three years. She promised to freeze income taxes, double a renovation tax credit for those caring for seniors or loved ones with disabilities and provide a tax credit to BC Ferries users in ferry-dependent communities.

"British Columbians care passionately about their own ability to look after the people they love. People care about being able to have a job," said Clark, whose party has been in power since 2001. "People care about having more money in their pocket.

"Those things really matter to people, and there is only one party that has a plan to deliver tax cuts, to keep government small and to make sure that we are creating jobs for ordinary working British Columbians."

The Liberals and NDP also zeroed in on the Port Mann and Golden Ears bridges in a bid to attract voters in key Surrey and Delta ridings. The Liberals would cap annual tolls at $500, but the NDP upped the ante with a promise to eliminate tolls entirely on the bridges connecting the suburban cities to Vancouver.

Clark dismissed the NDP promise as a costly "scheme" that would ultimately result in tax hikes. Her party's promise would cost about $30 million annually.

Both bridges are still in the red, years after being built. This year's provincial budget projected the Port Mann Bridge would lose $88 million in 2016-17 and $90 million in 2017-18. The Golden Ears Bridge lost $45.2 million in 2015.

NDP Leader John Horgan said he would release the cost of his plan to eliminate tolls on Thursday when his party unveils its platform. He said the fees unfairly penalize commuters south of the Fraser River and pushed them to the toll-free Pattullo and Alex Fraser bridges, worsening congestion.

"For Christy Clark, the person who imposed those tolls on people, it's laughable that she would say that it's a 'scheme,' " he said in an interview. "The B.C. Liberals have been putting costs on the backs of people and then claiming that they're leaving more money in people's pockets."

Horgan is also promising to freeze BC Hydro rates, a pledge that comes barely a week after rates jumped by 3.5 per cent, following a BC Hydro warning in November that rates would climb another 16.5 per cent over the next four years.

Although the election campaign officially begins Tuesday, Horgan kicked off the NDP's campaign in Surrey on Sunday and visited North Delta on Monday. The region is likely to be a key focus for both the Liberals and NDP, with one extra riding up for grabs in Surrey after redistribution.

Clark delivered her party's platform at Mobify, a Vancouver-based software company. She announced plans to teach coding starting in Grade 6, establish an "innovation hub" in Vancouver's Robson Square featuring a new University of British Columbia data science centre, and create 1,000 new post-secondary spaces in science, technology, engineering and math.

"We're going to create a new Silicon Valley right here in Canada's Pacific Gateway," she said.

Clark campaigned in 2013 on eliminating the province's debt through revenue from a liquefied natural gas industry, but her goals on Monday were more modest -- aiming for three LNG plants "moving to construction" by 2020.

The Liberal platform also promised to cut the small business tax to two per cent, phase out provincial sales tax on electricity for all businesses and commit to four more balanced budgets. It touted previous promises including eliminating unpopular medical services premiums over the long term.

The Green party has already unveiled several planks in its platform, including a climate change plan that would more than double the carbon tax over four years while spending $275 million to create clean technology jobs.