Pierre Poilievre's big day is almost here. The countdown for Canadian families is over.

Three billion dollars in child care payments roll out in a single day on Monday — a pre-election windfall that has been trumpeted for months by government ads and a carefully crafted communications strategy.

That campaign included the employment minister in a seemingly desperate bid to find 200,000 families "at risk" of missing out on the enhanced Universal Child Care Benefit, an effort that has so far turned up only a fraction of the missing.

It's not for lack of trying.

Press release after press release, and event after event, the government warned of "an important issue that has arisen with the delivery of the Universal Child Care Benefit."

Poilievre, right, and Conservative MP Royal Galipeau pose with families at a Giant Tiger store in Ottawa last Sunday, one of many events Poilievre has done to promote tomorrow's rollout of Universal Child Care Benefit cheques. (CBC News)

"Shortly after being appointed, I was briefed that approximately 200,000 families would not get their money because they were not signed up," Poilievre wrote CBC News.

"I was shocked to learn that hard-working families would miss out on almost $2,000 for each child under six and $720 for each child 6 through 17," the statement said. (In fact, the annual taxable amount is $1,920 for those under six.)

Poilievre will reveal exactly how many missing families he's found in two or three weeks' time.

It's not more than 10,000, though Poilievre's office says it is happy with results so far, suggesting it's hard to reach people to fill in an online form.

The opposition sees another motive at work.

"We know that this government doesn't hesitate to keep money from the most vulnerable by not spending it. It's done that with veterans, it's done that with EI, it's done that with people with disabilities," said NDP critic Jinny Sims.

"What is the government's real agenda here? Electioneering."

A great day for families! <a href="https://twitter.com/pmharper">@pmharper</a>'s boosted UCCB cheques started printing <a href="https://twitter.com/hashtag/Winnipeg?src=hash">#Winnipeg</a> <a href="http://t.co/AXYQJW9nO8">http://t.co/AXYQJW9nO8</a> <a href="https://twitter.com/hashtag/cdnpoli?src=hash">#cdnpoli</a> <a href="http://t.co/GhRuTYCEyV">pic.twitter.com/GhRuTYCEyV</a> —@PierrePoilievre

Calculating missing families

The vast majority of Canadian families were getting their money anyway.

Before it was expanded this year to include children older than six, the UCCB had a national uptake rate of more than 95 per cent.

In Quebec, more than 98 per cent of eligible families are already in the database. At the lower end, that figure is 92 per cent for Saskatchewan and just 82 to 89 per cent in the three territories.

Before the changes, 1.6 million families were receiving monthly payments. Now, four million families with children under 18 are eligible.

Most of them — some 3.8 million — are already signed up, because they applied for either the UCCB or the Canada Child Tax Benefit in the past. (It's the same form.)

But that wasn't good enough for Poilievre.

Documents released to CBC News under Access to Information show his department going to some lengths to calculate how many families could miss out, and where they live. But they don't reveal much:

In one undated analysis, a calculation on that number is redacted, citing exemptions normally used to protect sensitive political information.

A second calculation applied current UCCB uptake figures to regional Statistics Canada data and came up with the 200,000 estimate.

A revised analysis was completely redacted, save for a table breaking down families needing to apply by geographic location.

A third document had different regional estimates, but no methodology given.

Why did they need to estimate where the missing families might live?

For starters, it meant Poilievre or his junior minister, Candice Bergen, could issue event-specific press releases suggesting how many local families hadn't yet signed up.

Looking for the 30 families in <a href="https://twitter.com/hashtag/Montmagny?src=hash">#Montmagny</a> not yet signed up for the boosted <a href="https://twitter.com/hashtag/UCCB?src=hash">#UCCB</a> <a href="https://twitter.com/hashtag/YourKidsYourWay?src=hash">#YourKidsYourWay</a> <a href="http://t.co/OODE6HOX8f">pic.twitter.com/OODE6HOX8f</a> —@PierrePoilievre

On July 7, Poilievre warned 30 families in Montmagny, Que. not to miss out on their money. A June 29 visit to Dryden, Ont. was on the hunt for 40 families.

On May 8, Bergen's headline warned about "almost 10,000 Montréal families" (though the figure cited in the release was 8,400.)

And so on, back to the first April event, targeting the estimated 32,000 families in Greater Toronto.

Who's missing?

Message event proposals released to CBC News suggest the government has a sense of who hasn't signed up. Look at some of the "stakeholders" they identify:

Parent groups, particularly those with teens aged 14-18.

Recent immigrants to Canada.

Aboriginal organizations.

But with an election afoot, opposition critics suggest the ministers' recent travel was less about who's missing and more about who's voting, particularly in battleground ridings.

"Isn't it interesting, [Poilievre is] always popping up in areas where they want to shore up the Conservative vote?" said New Democrat Sims.

Liberal critic Scott Brison says the minister hasn't been to First Nations communities to promote sign-ups because they won't vote Conservative.

"This is not about finding missing families... this is all about promoting their vote-buying scheme," Brison said. "His entire tour should be paid for by the Conservative Party of Canada."

<a href="https://twitter.com/PierrePoilievre">@PierrePoilievre</a> If you know there are *1510* families that need to sign up, wouldn’t you also know who they are? —@mrpatmciver

Poilievre's office denies any conspiracy theory. The minister goes where he's invited by local MPs or stakeholders, his office says. Some UCCB events were planned to take advantage of travel on other official business.

About those letters...

Poilievre's department is in charge of the message but it's the Canada Revenue Agency that actually delivers benefits.

Before the budget had even passed, CRA sent 570,000 letters to parents asking them to confirm their children's information before July's big boost. The letters targeted "dormant" cases where payments ceased because children had grown too old for the existing UCCB or incomes were too high for the CCTB.

One Edmonton mom found her letter, confirming information CRA already had, "a little rich," and told CBC it read like a Conservative ad at taxpayers' expense.

CRA said it needed updates to make sure payments didn't go astray after custody changed, people moved or someone died.

Sims says it's "truly amazing" CRA wouldn't know this already.

"When [families] fill out their taxes, they write their dependants on that," Sims said. "Surely the quickest way to make sure that everyone is covered is to go through the data they already have.

"That doesn't require photo ops, that actually requires work," she said.

But the CRA says it can't search tax data to find information for another purpose. Plus, tax forms don't collect all the information required.

Timing is everything

Poilievre's office said the enhanced benefit was a big job for CRA. Payments couldn't start when they took effect, Jan.1, because the agency needed months to prepare.

Et voila, pre-election summer rollout, super-sized by retroactive payments for the past six months.

In 5 days until millions of kids benefit from increased <a href="https://twitter.com/hashtag/UCCB?src=hash">#UCCB</a> payments <a href="https://twitter.com/hashtag/YourKidsYourWay?src=hash">#YourKidsYourWay</a> <a href="http://t.co/P2Fa8MBA3G">pic.twitter.com/P2Fa8MBA3G</a> —@PierrePoilievre

The CRA takes about 80 days to process payments after families sign up.

At first, a May 1 sign-up deadline was floated as a communications hook, counting down to July 20. The deadline was later extended to May 15.

In truth, Canadians can apply any time — but the money might not arrive before the election.

"This is not about public service timing, this is about Conservative electioneering timing," Brison said.

Every government program has uptake issues, the former Liberal cabinet minister added.

"This is not a new thing. Are the Conservatives going out to find all the people who have not applied for GIS [Guaranteed Income Supplement for seniors] over the last 10-12 years?"

The minister's office says their 200,000 families estimate is in fact a conservative one. Their hunt for the missing continues.