CHICAGO (CBSNewYork) — Chicago Bears legend Mike Ditka is not mincing words when it comes to Republicans wavering in their support for presumptive GOP presidential nominee Donald Trump.

“The Republican Party has its head up its a** – if he’s the candidate, you’ve got to get behind him,” the former Super Bowl-winning coach told the Chicago Tribune. “It does the party no good. They’re a bunch of a***holes.”

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Ditka said in March that he would probably vote for the billionaire in November.

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“If you want good things to happen, you can vote for him, and if you don’t, you don’t,” Ditka told the Tribune. “But don’t b**** about it after the fact.”

Ditka also told the Tribune that he declined Trump’s offer to speak at the Republican National Convention in Cleveland next month.

“I can help him, but I don’t know if I can give a speech at the convention,” the football Hall of Famer explained. “I don’t travel much anymore except between Chicago and Florida, and giving a speech at a convention isn’t really my style.”

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Bloomberg Politics reported Tuesday the Trump campaign was trying to line up Ditka, Mike Tyson and NASCAR CEO Brian France to appear at the convention. Tyson and France told Bloomberg that they would not attend.