CORALVILLE, Iowa — Presidential candidate Bernie Sanders let loose a volley of sharp attacks against Michael Bloomberg on Saturday night, accusing the former New York mayor in his bluntest language yet of positioning himself to buy the election and vowing to stop him from doing so.

“Tonight we say to Michael Bloomberg and other billionaires: Sorry, you ain’t gonna buy this election,” said Sanders (I-Vt.), prompting loud cheers from supporters.

The fiery comments, which marked an escalation from earlier and less direct criticism from Sanders, underscored how Bloomberg’s recent steps toward entering the Democratic primary have roiled the contest. They also offered a preview of the jabs Bloomberg could face from other candidates if he decides to jump in the race.

The leading liberal candidates, Sanders and Sen. Elizabeth Warren (D-Mass.), have significant ideological differences with Bloomberg that would probably flare up if the former mayor challenges them.

Sanders delivered his remarks at a campaign rally here that marked the end of a two-day swing through this first caucus state with Rep. Alexandria Ocasio-Cortez (D-N.Y.). Sanders will continue campaigning in Iowa on his own Sunday and Monday.

Bloomberg recently walked back his earlier declaration that he would not run for president, moving to file paperwork for the contest, even as he has stopped short of officially entering. A Bloomberg adviser said Friday that if Bloomberg does get in the race, he would not aggressively compete in the first four caucus and primary states. Sanders knocked him over that strategy.

“You’re not going to get elected president by avoiding Iowa, by avoiding New Hampshire, South Carolina and Nevada,” warned Sanders. “You’re not go to buy this election by spending hundreds of millions of dollars on media in California. Those days are gone.”

A Bloomberg adviser did not immediately respond to a request for comment.

Sanders touted his nationwide network of volunteers and said their support would ultimately help him prevail in the race.

Bloomberg is one of the world’s wealthiest people. Should the billionaire businessman enter the race, he would bring considerable financial resources that would allow him to blanket the airwaves with advertising, hire scores of staffers and deploy pricey strategists to guide his bid.

Criticizing billionaires is a staple of Sanders’s stump speeches. He frequently calls for combating income inequality and reining in the power of the wealthiest Americans by raising their taxes.

“What this campaign is about is understanding that the working families of this country are sick and tired of working longer hours for lower wages while almost all new wealth and income goes to the top 1 percent,” Sanders said Saturday, his voice reaching a scream.

A few moments later, he called out Bloomberg by name again. “I say to Michael Bloomberg and his billionaire friends: That is going to change.”