The rules previously required candidates to have hundreds of thousands of individual donors in order to qualify, but the DNC on Friday removed the requirement for the February 19 debate in Nevada. Bloomberg had been ineligible to participate in past debates at least partly due to bankrolling his campaign with his own fortune instead of individual contributions.

“To now change the rules in the middle of the game to accommodate Mike Bloomberg, who is trying to buy his way into the Democratic nomination, is wrong,” said Sanders campaign senior adviser Jeff Weaver in a statement. “That’s the definition of a rigged system.”

Newsweek reached out to the DNC for comment but did not receive a reply in time for publication.

The new rules require candidates to have at least one pledged delegate from the Iowa caucus or the New Hampshire primary, or poll at 10 percent or higher in four national polls in order to participate. They can also qualify by getting at least 12 percent in two sanctioned polls.

A late entry to the Democratic field, Bloomberg had previously failed to meet both polling and fundraising thresholds to participate in the debates. It’s unclear whether his polling numbers will qualify him for the Nevada debate, but some recent polls have shown him on the rise.

Rival candidates have accused Bloomberg of trying to “buy” his way into the nomination. Sanders in particular has focused a great deal of his campaign on income inequality and expressed early doubts about the viability of Bloomberg’s candidacy.

“I don’t believe that Mr. Bloomberg is going to succeed,” Sanders told Politico shortly after Bloomberg announced he was running. “Because I think at the end of the day, people of this country do not want to see a billionaire buy an election, and that is precisely what Mr. Bloomberg is trying to do.”

Perhaps unsurprisingly, the Bloomberg campaign had a different take on the change, while insisting that their candidate has the best chance of defeating President Donald Trump in November.

“We are thrilled that voters could soon have the chance to see Mike Bloomberg on the debate stage, hear his vision for the country, and see why he is the strongest candidate to defeat Donald Trump and bring our country together,” said Bloomberg campaign manager Kevin Sheekey in a statement.

Bloomberg will not be taking part in the next Democratic debate, operating under the old rules in New Hampshire on February 7. However, entrepreneur Andrew Yang will be joining the event, after being left out of the previous debate in Iowa.