DES MOINES, Iowa (AP) — A top aide to Democratic presidential candidate Tom Steyer, in Iowa, has privately offered campaign contributions to local politicians in exchange for endorsing his White House bid, according to multiple people with direct knowledge of the conversations. The overtures from Pat Murphy, a former state House speaker who is serving as a top adviser on Steyer’s Iowa campaign, aren’t illegal — though payments for endorsements would violate campaign finance laws if not disclosed. There’s no evidence that any Iowans accepted the offer or received contributions from Steyer’s campaign as compensation for their backing. But the proposals could revive criticism that the billionaire Steyer is trying to buy his way into the White House.

Several state lawmakers and political candidates said they were surprised Steyer’s campaign would think he could buy their support. Tom Courtney, a former Democratic state senator from southeastern Iowa who’s running for reelection to his old seat, told The Associated Press the financial offer “left a bad taste in my mouth.” Alberto Lammers, Steyer’s campaign press secretary, said Murphy was not authorized to make the offers and that the campaign leadership outside of Iowa was unaware that he was doing so until the issue was raised by The Associated Press.

Courtney declined to name Murphy as the Steyer aide who made the offer, but several other local politicians said they received similar propositions, and all confirmed the proposal came from Murphy himself. Another, Iowa state Rep. Karin Derry, said Murphy didn’t explicitly offer a specific dollar amount, but made it clear Derry would receive financial support if she backed Steyer. Lammers, Steyer’s campaign press secretary, said the candidate hasn’t made any individual contributions to local officials in Iowa and won’t be making any this year. In an email, Lammers said Steyer’s endorsements “are earned because of Tom’s campaign message,” and distanced the candidate from Murphy.

The overtures do not appear to have made much of a difference for Steyer. Aside from Murphy’s support, Steyer has received the endorsement of just one Iowan since entering the race in July — former state Rep. Roger Thomas. Experts say a campaign could violate campaign finance laws if they don’t disclose payments for endorsements.

The billionaire businessman built his fortune in banking and investment management before turning to politics, and though he’s never held public office he invested tens of millions of dollars in political activism and electoral politics before launching his presidential bid this year. Prior to his presidential run, Steyer’s most recent focus was a multi-million-dollar, pro-impeachment campaign, and as the U.S. House takes up the issue, he’s argued he’s put it on the national agenda. Steyer has largely self-funded his presidential campaign, spending $47.6 million of his own money in the first three months since launching his bid, much of that on online fundraising and advertising. Steyer qualified for the November debate, but he remains at the back of the pack in early-state and national polls.