Washington (CNN) As Republican angst about Donald Trump grows closer to panic, some longtime GOP strategists and donors are discussing creative ways to cut their presumptive nominee loose at their convention in July.

There's renewed talk in some Republican circles to find a way out as Trump lags big time behind Hillary Clinton in several new polls, and he has the highest unfavorable rating of any candidate for a major party on record -- 70% in this week's Washington Post-ABC poll.

One source with knowledge of these discussions underscores to CNN, however, that all of the ideas being bandied about now are highly unlikely to see fruition -- mostly because this kind of move to get rid of a nominee elected by GOP primary and caucus voters would be unprecedented. And a second source says he has spoken directly to senior GOP operatives with extensive convention experience who are actively exploring how to dump Trump.

Still, here are some options they are exploring:

Free delegates at the convention

Right now the ideas are focused in and around freeing convention delegates who are bound to Trump.

One way to do that would be to survey the delegates and find out who is willing the go with someone else in a second ballot. The challenge with this, according to a source familiar with the talks, is there has to be a lot of specificity. Delegates will have to be asked not just if they are willing to abandon Trump, but also whether they would then be willing to vote for a specific candidate instead.

A huge hurdle for "Never Trump" Republicans is that the alternatives -- Ted Cruz and others -- are still considered by many to be "untenable."

Sen. Jeff Flake, an Arizona Republican who opposes Trump and has been a sharp Cruz critic, said it's "too late" to get rid of Trump at the convention.

"I'm told the rules are such that it's very difficult to do," Flake said.

"If poll numbers just continue to go south, you'll have, you know, more people saying, 'Hey is it too late to make a change?' I don't think that's gonna happen. It's just too late in the process and obviously there are a lot of dedicated supporters out there that would object."

Mike Shields, a former Republican National Committee chief of staff and expert on delegates and convention rules, said a break from Trump by the delegates would be unprecedented.

"The delegates are bound right now to nominate Donald Trump. They would have to unbind themselves, go through a process of changing the rules and go against the wishes of the voters," Shields said. "That's never happened before and I think it would be a difficult, heavy lift."

There is a group of people -- including Eric O'Keefe, a former top fundraiser for Cruz -- that recently formed a group they're calling "Delegates Unbound." They are working on a robust effort to convince delegates that they have the authority and the ability to vote for whomever they want.

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A source working with the group told CNN that they are going to try to not only directly communicate with the delegates but also try to raise money to buy TV ads. This source insists the anti-Trump energy is out there among delegates but they just have to coordinate and harness it -- which is no easy task.

Other people working on this are A.J. Spiker, a former Iowa GOP chairman and Rand Paul supporter, and strategist Dane Waters.

Using the Rules Committee

Another idea is to use the RNC convention rules committee to try to pass a rule freeing all the delegates to vote for whomever they want on the front end.

Conservatives Eric O'Keefe and David Rifkin, Jr., wrote an op ed in the Wall Street Journal this week advocating the idea, and pushing back on those who say it's not possible because state party rules, not national party rules, dictate whether delegates are bound.

"These statutes can't be legally enforced. When Republican delegates arrive in Cleveland to select their party's nominee, they should recognize that they are bound only by their consciences," wrote O'Keefe and Rifkin.

"A candidate who cannot win the support of a majority of Republican delegates voting their consciences does not deserve to be the nominee and certainly has no legal right to be," they argued.

But that effort could be problematic at the convention, warns Sen. Susan Collins of Maine, who has yet to endorse Trump.

"Donald Trump has been chosen by a majority of the delegates to be the Republican nominee, and I think any attempt at the convention to overturn the will of the delegates would result in a rebellion," Collins told CNN.

'Conscience clause'

Another idea is to dust off an addition to the rules at the 1976 convention, called a "conscience clause," which would allow delegates bound to a candidate to be unbound if they feel the candidate did or said things they disagree with between their state's primary or caucus and the convention.

At this point, sources familiar with these discussions insist neither the congressional leadership nor the RNC is involved in these talks at all.

And, sources underscore, most of these ideas would be incredibly hard to execute -- never mind that they understand it would feed into the very real anger at the "establishment" among GOP voters that fueled Trump's victories in the first place.

It would likely prove Trump's point: party systems are rigged and can't be trusted.

Romney redux?

The problem for Republicans who are critical of Trump is they lack a viable alternative. One source stressed that Mitt Romney and those close to him have calculated that it's not feasible for him to jump into the race. And while some on the Hill are aware of such discussions to dump Trump, several GOP sources said that Republican leaders are staying away from any such effort to remove him. One top Republican said bluntly: "We are stuck with him."

At a private lunch meeting at the National Republican Senatorial Committee headquarters this week, GOP lawmakers actively discussed their 2016 prospects. But two senators who attended say they didn't even discuss Trump, a sign that many are resigned to him being the nominee no matter how concerned they are.

Sen. Jeff Sessions, an Alabama Republican who is the Senate's most outspoken Trump backer, said it's time for the party to fall in line behind Trump.

"It would be just such a disaster," Sessions said of any effort to oust Trump.