Donald Trump is making an issue of Hillary Clinton’s relationship with Irish businessman Denis O’Brien.

O’Brien is listed by the Clinton Foundation as having made $10 million to $25 million in donations to the charity as of June 2016, The Irish Independent reports. The Irish government is also listed as fifth among 19 nations that have donated to the Foundation, contributing in the range of $5 million to $10 million.

Bill Clinton and Denis O’Brien

“This attack may not be deliberate Trump payback for overt political assaults on him by senior politicians in the Dáil this year, but it should be enough to worry Irish voters,” Colum Kenny writes in The Irish Times. “With the E.U. going after tax breaks for U.S. jobs here, we do not need a pissed-off president in the White House.”

Here’s the email the Trump campaign sent to reporters, which quotes extensively from Irish and U.S. media reports.