US President Donald Trump and his would-be Democratic challenger Michael Bloomberg will air duelling Super Bowl ads, each costing about $10m (£7.6m).
The deep-pocketed Bloomberg campaign has secured a 60-second slot next month targeting the president.
The Trump campaign’s Super Bowl purchase is also for a minute.
The game on 2 February is America’s biggest annual sporting event and is expected to be watched by more than 100 million people in the US alone.
It boasts some of the most expensive television commercial slots of the year.
The National Football League final will be staged on the eve of the Iowa caucuses, the first in a series of state-by-state votes to pick the Democratic candidate who will eventually challenge Mr Trump, a Republican, for the White House in November’s election.
Mr Bloomberg is one of 14 candidates vying to be the Democratic standard-bearer. He has unleashed an onslaught of campaign spending since jumping into the presidential race relatively late, back in November.
He has spent more on digital and TV advertising than any other candidate so far, almost $170m, according to ad tracking firm Advertising Analytics.
It predicts Mr Bloomberg may spend up to $400m on ads over the next crucial couple of months.
In March, voters from 13 US states will pick their preferred Democratic White House candidate in an electoral bonanza known as Super Tuesday.
A spokesman for the Bloomberg campaign told the New York Times the “biggest point” of the Super Bowl ad “is getting under Trump’s skin”.
By “taking the fight to Trump”, Michael Frazier said, “the ad is part of Mike’s strategy of running a national campaign that focuses on states where the general election will be decided, parts of the country that are often overlooked”.
The Trump campaign’s Super Bowl purchase, first reported by Politico, is expected to entail either a single minute-long advert, or two separate 30-second commercials.
“Super Bowl ad is an indicator that the @realDonaldTrump campaign is ramping up as 2020 begins,” tweeted the Trump campaign’s communication director Tim Murtaugh.
“Also big plans to spend on outreach to women, blacks, Latinos & religious voters.”
The splurge represents just a fraction of Mr Trump and Mr Bloomberg’s bulging campaign war chests.
Last week, the Trump campaign announced it had raised a combined $463m with the Republican National Committee last year.
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For Mr Bloomberg, his self-financed campaign’s spending will barely make a dent in his personal fortune.
The former New York City mayor’s net worth is $52bn, according to Forbes – 17 times more than Mr Trump.
Last month, Mr Bloomberg denied trying to buy the White House, telling CBS News of his Democratic rivals: “I’m doing exactly the same thing they’re doing, except that I am using my own money.
“Nobody gives you money if they don’t expect something. And I don’t want to be bought.”
Announcing his candidacy, the businessman said he was standing to “defeat Donald Trump”.
Mr Trump taunted “little Michael”, saying his fellow New York tycoon “doesn’t have the magic” to make it to the White House.
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