Patrick Brown and his Ontario PCs are making clear that they are in it to win it, offering a platform jam-packed with promises designed to appeal to that crucial swath of voters who aren't bound to a political ideology.

As Kathleen Wynne's Ontario Liberal Party unabashedly tries to woo the left, the Progressive Conservatives are seeing their chance to grab hold of the centre.

The big question is whether those middle-of-the-road voters will trust Brown to be a moderate if he wins power. After all, he spent nine years on Stephen Harper's backbenches and he's leading the party that brought Ontario the Common Sense Revolution under Mike Harris.

"For a lot of people, their vote is driven by who can they trust," said Nelson Wiseman, political science professor at the University of Toronto, in an interview Monday.

To try to win that trust, Brown and the PCs released their full platform on the weekend, more than six months ahead of voting day. It's in a slickly-designed glossy magazine entitled "People's Guarantee." The guarantee part: if a PC government fails to bring in its five key promises, Brown will not run again.

My promise to you is that if the People’s Guarantee is not enacted in the first mandate of an Ontario PC government, I will not seek a second. <a href="https://twitter.com/hashtag/onpoli?src=hash&ref_src=twsrc%5Etfw">#onpoli</a> <a href="https://twitter.com/hashtag/peoplesguarantee?src=hash&ref_src=twsrc%5Etfw">#peoplesguarantee</a> <a href="https://twitter.com/hashtag/PCPO?src=hash&ref_src=twsrc%5Etfw">#PCPO</a> <a href="https://t.co/CbIZqh7art">pic.twitter.com/CbIZqh7art</a> —@brownbarrie

Two of the five key pledges are red-meat pocketbook promises: a 22.5 per cent tax cut for the middle class and a further 12 per cent reduction in the average hydro bill.

Two others are absolutely crucial to softening the PC party's image as slashers-and-burners: refunding up to 75 per cent of families' daycare costs, and committing to spend an extra $1.9 billion on mental health over the next decade.

The PCs' child-care refund would give:

$6,750 to a single parent earning $35,000 per year with a child under six

$5,700 to a couple earning $100,000 with two school-age children

Longtime Liberal strategist Warren Kinsella describes the child-care rebate and mental health funding moves as both capital-L and small-L liberal.

"This ain't the PC party of Harris no more — it's the PC party of (BIll) Davis," writes Kinsella on his blog.

PC Leader Patrick Brown addresses the Ontario Progressive Conservative Party convention in Toronto on Saturday, Nov. 25, 2017. (Chris Young/The Canadian Press)

Notably, Brown is not vowing to dismantle several of the Wynne government's key recent initiatives, including free prescription drugs for children and young adults, grants that cover the costs of tuition for lower-income families, or expanded rent control.

That suggests the PCs have learned lessons from previous election losses in which their controversial promises — to cut 100,000 public sector jobs or fund religious schools — led to defeat.

Wiseman describes the platform as a fulsome but cautious agenda with nothing radical in it. "The Conservatives want to make sure this election is not about them, but is about the Liberals and Kathleen Wynne," he said.

The Liberals are already trying to persuade voters that Brown can't actually provide more services while reducing taxes.

There are $12 billion in spending cuts in the PC platform, said Deputy Premier Deb Matthews.

"They don't talk at all about where those cuts are going to be made, but we know they will come from health care and they will come from education, because those are the biggest parts of the budget." Matthews told reporters Monday at Queen's Park.

The Ontario Progressive Conservative platform for the 2018 election features a signed "guarantee" from party leader Patrick Brown that if he fails to bring in his five key promises in his first term in office, he will step down. (Mike Crawley/CBC)

The platform shows "savings" of $6.1 billion over its four-year budget forecast through a "value-for-money audit" of government programs, plus $6.3 billion in reduced revenue from eliminating the Liberals' cap-and-trade program, which requires businesses to pay for their carbon emissions.

But even Matthews, who is co-chair of the Ontario Liberal re-election campaign, grudgingly admits the PC platform hits a populist tone.

"They've done some good focus-group testing, I think they're raising some issues that are politically advantageous," Matthews said. "They did a good job on the marketing side. I think they did not so good a job on coming clean with the people of Ontario."

Kinsella calls the magazine-style cover of the platform brilliant.

"The genius of the PC platform is that they actually printed [their key promises] right on the cover," writes Kinsella. "It ensures the stuff they want you to remember will be remembered."