On the Senate floor July 24, Sen. Ted Cruz (R-Tex.) accused "career politicians" in Congress of "looting the tax payer to benefit wealthy, powerful corporations." (AP)

Firebrand Republican senator and presidential candidate Ted Cruz on Friday rushed across a line rarely crossed on the Senate floor: He accused the leader of his party, Majority Leader Mitch McConnell, of lying to his colleagues.

"What we just saw today was an absolute demonstration that not only what he told every Republican senator, but what he told the press over and over and over again, was a simple lie," Cruz said Friday morning. "We know now that when the majority leader looks us in the eyes and makes an explicit commitment, that he is willing to say things that he knows are false. That has consequences for how this body operates."

Cruz's remarks laid bare, in the most august of settings, simmering tensions between the activist wing of the Republican Party and the mainstream party establishment.

Prompting Cruz's outburst: McConnell's move to set up amendment votes on a must-pass transportation bill. After senators voted to consider the bill, McConnell (R-Ky.) set up votes on two controversial measures -- a repeal of the Affordable Care Act, and a reauthorization of the Export-Import Bank of the United States -- and did it in such a way that will make it difficult for other amendments to be considered.

That move incensed Cruz -- who had announced his intention to offer other amendments, and who, like many conservatives, strongly opposes the bank's reauthorization, though it enjoys support from a supermajority of his Senate colleagues. While McConnell has personally spoken against Ex-Im reauthorization, Democrats said in June he had agreed to schedule an Ex-Im vote in order to get highly divisive trade legislation passed.

But McConnell at the time denied that any deal had been struck, and Cruz said Friday the same assurance was given in a private Republican conference meeting:

We had a Senate Republican lunch where I stood up and I asked the majority leader very directly, what was the deal that was just cut on [trade legislation, and was there a deal for the Export-Import Bank? It was a direct question. I asked the majority leader in front of all the Republican senators. The majority leader was visibly angry with me that I would ask such a question, and the majority leader looked at me and said, "There is no deal, there is no deal, there is no deal."

"Like Saint Peter, he repeated it three times," Cruz added.

Senators generally refrain from impugning their colleagues on the floor -- a practice codified in Senate Rule XIX: "No Senator in debate shall, directly or indirectly, by any form of words impute to another Senator or to other Senators any conduct or motive unworthy or unbecoming a Senator."

In recent weeks, McConnell had signaled that the transportation bill would be a likely vehicle for Ex-Im reauthorization. Before Cruz spoke, McConnell said he had not choice but to allow the Ex-Im vote, saying that bank supporters have "made it clear they're ready to stop all other amendments if denied that opportunity."

"They have already proven they have the votes to back up the threat as well," he said, referring a June 10 test vote showed 65 senators supporting Ex-Im reauthorization. "This presents a challenge for the senate and to opponents of the Ex-Im bank, like myself, in particular."

Cruz, a famously fierce opponent of the Affordable Care Act, was also not at all mollified by McConnell's move to bring up a repeal vote -- the first time that GOP priority has come to the Senate floor this year.

In his speech Friday, Cruz called it "empty showmanship."

"We'll have a vote on repealing Obamacare," he said. "The Republicans will all vote yes; the Democrats will all vote no. It will be at a 60-vote threshold. It will fail. It will be an exercise in meaningless political theater."

McConnell spokesman Don Stewart declined to comment on Cruz's remarks.