Anti-Trump forces are launching what the organizer of the movement describes as a “multi-pronged” approach to stop Donald Trump at the Republican National Convention, one that could cause chaos on the convention floor.

Colorado delegate Kendal Unruh is the leader of the effort, which centers around changing the convention rules to include a “conscience clause” that would allow delegates bound to Trump to vote against him, even on the first ballot at the July convention.

"If any such delegate notifies the secretary of his or her intent to cast a vote of conscience, whether personal or religious, each such delegate shall be unbound and unconstrained by these rules on any given vote, including the first ballot for the selection of the Republican nominee for President of the United States, without the risk of challenge, sanction, or retribution by the Republican National Committee,” the resolution reads.

A lot would need to happen for Unruh’s efforts to prevent Trump from capturing the nomination. A majority of the 112-member Rules Committee would need to vote in favor of the change, and then enough of the convention's 2,472 delegates would need to invoke the “conscience clause” to reject Trump. But the movement is significant in that it is the most organized plan yet for opposing the real estate mogul’s nomination.

Two sources involved in Unruh’s effort to change the committee’s rules say they’ve already secured ten Rules Committee delegates to vote for the resolution, including Unruh and her fellow Colorado Rules Committee member Guy Short. The other eight could not be independently confirmed. Unruh declined to release their names because she said she and others involved in the efforts had received threats from Trump supporters.

Even some in the Republican establishment in Colorado have warned Unruh her “future in politics is over.” But she has no plans to back down.

“I have been a good soldier for the last few nominees. Even though they have not been my first choice I have always fallen in line. I just can’t do it this time. They just don’t understand, it’s not just a vote — it’s the future of our party,” she said.

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Unruh says she’s been hearing growing interest in her proposal since it began to draw media attention last week, and many of the delegates she hears from already believe they aren’t legally bound under Republican National Committee rules to back Donald Trump. It’s an obscure interpretation of the party rules that’s gained traction in recent months as dissatisfaction with the presumptive GOP nominee has grown.

The resolution, then, is meant to give delegates “cover.”

“I call it the permissions slip from mom. It gets to the nitty gritty of the fact that Republicans tend to be rule followers. They don’t like distraction or disunity or being labeled a troublemaker or a rabblerouser and they love decorum,” Unruh said.

Calls for a challenge to Trump at the convention have grown since he locked up the nomination three weeks ago as Trump has stubbornly refused to moderate his tone and alienated many within his own party with controversial rhetoric on Muslims and race-based attacks on a judge overseeing a case against him. He now lags Democrat Hillary Clinton in multiple national polls, and many Republicans have warned if he isn’t able to right the ship in the next month the convention coup is a very real possibility.

Donald Trump’s strategists involved with delegate operations have downplayed the prospect, with one adviser telling NBC News they believe they have the “overwhelming majority” of delegates on the Rules Committee supporting Trump.

“All of our surveying — in the general sense of the word, not in the particular sense of the word — of the delegate situation tells me there’s no real appetite in changing the rules, or opposing Mr. Trump,” the adviser said.

And as recently as last weekend, another strategist who had been involved in the delegate efforts said during their meetings the previous week, “the prospect of a contested convention didn’t come up once.”

“There’s no concrete plan,” the strategist said, “so that’s why I don’t take it too seriously."

Unruh says the Trump campaign is underestimating her effort.

“They’re anticipating we’re not going to be as organized as we are,” she said.

Unruh tapped Regina Thompson, another Colorado delegate and Tea Party organizer who led Cruz’s delegate operation in the state and helped him elect his full slate of delegates to the convention there, to start building out the logistics of their operation. They’re looking at it as a whip operation, Unruh said, and they have a spreadsheet of key Rules Committee members she hopes to sway to ultimately gather the 56 votes she wants to pass the resolution.

They’ve tapped representatives in 25 states actively organizing support for the effort. They’ve named seven regional directors - in Arizona, Colorado, Illinois, Iowa, Louisiana, Utah and Washington - and are working on securing whips in each delegation to keep track of the votes. And they gathered 30 interested activists, delegates, and alternate delegates on a conference call Thursday night to talk through their efforts, with a follow-up call for delegates nationwide planned this Sunday.

But Unruh acknowledged a major challenge to her effort: They have “no clue” what happens if they’re successful. They purposely haven’t sought out or endorsed an alternative to Trump, acting under more of an “if we build it, the candidate will come” mentality, so as to avoid turning off supporters of any of Trump’s opponents.

“That is probably the toughest sell,” Unruh said. “I don’t know what the end game looks like and I don’t have the picture on the box yet — but I think I have another piece of the puzzle,” she said.

She believes “once the infrastructure is created, there’s going to be a strong party leader that jumps in.”

CORRECTION: A previous version of this article incorrectly identified Louisiana delegate Kim Fralick as a Rules Committee member supportive of a change to the rules. She was elected to the Credentials Committee.