Tea Party group: Shut down government over ObamaCare

Sen. Mike Lee (R-Utah) has threatened to vote against any spending bill that does not defund the healthcare law's implementation. He has met vocal criticism from several Republican senators, including Sen. Richard Burr (N.C.), who called it the "dumbest idea I've ever heard of."

But Tea Party Patriots said it will not support any GOP senator who agrees to fund the federal government if ObamaCare is included.

"For any Republican Senator to not join Sen. Lee by pledging to oppose continued funding for ObamaCare, it would be like saying, 'I was against the bill before I was for it,' " Martin wrote.

For America, led by Brent Bozell, also signed the letter.

— This post has been updated. A previous version misidentified Tea Party Patriots National Coordinator Jenny Beth Martin.