Former Republican president George W. Bush told donors that Texas Sen. Ted Cruz is his brother Jeb Bush’s most “formidable” opponent in the GOP primary, according to Politico.

Politico spoke to half a dozen donors at an Oct. 18 event in Denver. The attendees reported that Bush said “I just don’t like the guy.”

Bush also slammed Cruz’s alliance with runaway frontrunner Donald Trump, who has repeatedly mocked Jeb as “pathetic” and “low energy.”

“Bush said he found it ‘opportunistic’ that Cruz was sucking up to Trump and just expecting all of his support to come to him in the end,” a donor told Politico.

Bush “said he thought Cruz was going to be a pretty formidable candidate against Jeb, especially in Texas and across the South,” said another donor.

“[George W. Bush] sort of looks at this like Cruz is doing it all for his own personal gain, and that’s juxtaposed against a family that’s been all about public service and doing it for the right reasons. He’s frustrated to have watched Cruz basically hijack the Republican Party of Texas and the Republican Party in Washington,” another donor told Politico.

His brother repeatedly told donors, “You’re not going to see a lot of me” on the campaign trail.

Bush’s spokesman Freddy Ford denied Bush’s remarks. “The first words out of President Bush’s mouth last night were that Jeb is going to earn the nomination, win the election, and be a great President. He does not view Senator Cruz as Governor Bush’s most serious rival,” Ford said.

The event was organized by the GOP establishment to bolster Jeb’s campaign. But it managed to attract only one hundred donors by offering last-minute, reduced-price ticket sales to fill up the room, Politico added.

Despite raising $100 million from his super PAC Right to Rise USA, Jeb Bush managed to garner only $11 million for his campaign, mostly from maxed-out donors. Mired in sixth place and polling in single digits, he has cut back on campaign spending. The GOP establishment apparatchiks running his super PAC haven’t entirely helped their candidate: In August, they stumbled in their “shock and awe” campaign by sending an extremely awkward mailer to 86,000 Iowa households featuring a black man’s hand Photoshopped onto Jeb’s hip.

After initially declining to comment, the Cruz campaign issued a statement:

I have great respect for George W Bush, and was proud to work on his 2000 campaign and in his administration. It’s no surprise that President Bush is supporting his brother and attacking the candidates he believes pose a threat to his campaign. I have no intention of reciprocating. I met my wife Heidi working on his campaign, and so I will always be grateful to him.

Email Katie at kmchugh@breitbart.com.