Dissident delegates making a last-gasp attempt to prevent Donald Trump's nomination at the Republican National Convention say they will try forcing a state-by-state vote on the rules governing the gathering when it opens on Monday.

But even if the rebels succeed in even getting such a roll call to occur, it's one they seem very likely to lose.

"What will happen on the floor, if there's any attempt, is the party and Trump are going to rise against it," Paul Manafort, Trump's campaign chairman, told reporters on the convention floor on Sunday.

The convention's rules committee decisively defeated the dissidents seeking to make the changes late last week, thanks to an alliance between the Trump campaign and RNC leaders on that panel. Manafort said there was no longer a viable "stop Trump" movement, only some "malcontents" who don't represent the broader Republican Party.

The Trump opponents want to change the rule that requires delegates to vote for the candidate to which they were committed after state primaries and caucuses. Trump's nomination is essentially automatic under the current rules, as he has far more than the 1,237 delegates to required to win.

In what has become a bitter internal battle, a group of social conservatives also want to shift party decision-making away from GOP leaders to rank-and-file activists. They also want to ban lobbyists from serving on the 168-member Republican National Committee and prevent states from allowing independents and Democrats to vote in Republican primaries, which helped Trump.

Ken Cuccinelli, a former Virginia attorney general and Cruz adviser who's helped organize the conservative effort, said in an interview Sunday that Trump "had a chance to be the anti-establishment candidate, but he got in bed with the RNC" at the rules committee meeting.

Some rebellious delegates are threatening to walk out if they are thwarted, perhaps on Monday. Should that occur in significant numbers, that could leave television cameras panning across rows of empty seats.

"We won't sit around and coronate a king," said Colorado delegate Kendal Unruh, who like many insurgents has backed vanquished presidential contender Sen. Ted Cruz of Texas.

The full convention will consider the rules approved last week on Monday, and the rebels want to force a state-by-state roll call, with the chairman of each state delegation announcing the vote of its delegates.

They say if the question is decided by a voice vote of the entire convention, they don't trust the presiding officer to announce the results fairly.

To force that roll call vote, the rebels must gather signatures of a majority of delegates from at least seven states and submit them to convention officials.

It's questionable they have that level of support, and even if they managed to force a roll call vote, it is not likely to succeed. Shawn Steel, a RNC national committeeman from California, said Sunday his delegation was behind Trump "100 percent."

"It's the ultimate firewall," he said, referring to California, the largest of any delegation.

Separately, Cuccinelli and his allies would need signatures from at least 28 members of the 112-member rules committee to force votes on specific rules changes they want — a threshold they reached only rarely during the rules committee votes last week.