(CNN) - Conservative leader Paul Weyrich – who endorsed Mitt Romney’s presidential bid – has signed on to an open letter from more than two dozen movement activists to John McCain warning him not to select the former Massachusetts governor as his VP pick if he expects their support.
"If Governor Romney is on your ticket, many social conservative voters will consider their values repudiated by the Republican Party and either stay away from the polls this November or only vote down the ticket,” they write in a message posted online by a political action committee called “Government is Not God.”
The letter – topped by the headline “NO Mitt” - will run as a print ad in cities visited by McCain, the presumptive Republican nominee, beginning with his Arizona stop this weekend.
The group includes supporters of Arkansas governor Mike Huckabee like activists Gary Glenn and Janet Folger, along with conservatives who have long criticized Romney for his past stands on issues like abortion.
Weyrich endorsed Huckabee after Romney left the race. The activist’s opposition to the former governor marks a complete reversal from his position as recently as last month, when he told the National Journal that McCain was unlikely to select Romney as his running mate – but that he should.
"If he selects somebody bad from our point of view, it's going to be very difficult," he told the magazine. "It will reinforce prejudice against him. If he selects somebody pretty good, it'll be moderately helpful.... It would help if he selected Mitt Romney, but he won't."