WASHINGTON (AP) — In an extraordinary display of internal discord, the chairman of the Republican Party's rules committee is accusing top GOP officials of "a breach of our trust" by improperly trying to block a proposed change in bylaws that would make it harder for party leaders to nominate a fresh candidate for president.

Bruce Ash, RNC committeeman from Arizona, wrote a harshly worded email to the other 55 members of the GOP rules committee that he chairs.

The confidential email, obtained by The Associated Press on Saturday, was written days before party officials gather in Hollywood, Florida, for preliminary discussions about what rules the GOP will use at its presidential nominating convention this July.

Ash wrote the note at a time when some top Republicans consider the party's two leading presidential contenders, billionaire Donald Trump and Texas Sen. Ted Cruz, to be likely November election losers. Those leading Republicans have discussed how to replace Trump and Cruz with alternatives at the summer convention in Cleveland, Ohio.

It is possible that no contenders will have the 1,237 delegates needed to clinch the nomination at that gathering, which would produce the first GOP convention without a presumptive nominee since 1976.

Trump has bitterly clashed with party leaders over rules that he claims have been rigged against him, a charge party leaders deny.

Ash said he has "become troubled" during discussions with RNC Chairman Reince Priebus and other party officials that by not making the proposed change, GOP officials "could use their power to attempt to achieve a political result" at the nominating convention.

He said the convention's presiding officer could use existing rules to "unilaterally reopen nominations to allow a candidate to be nominated that is viewed as more acceptable, which is exactly what so many rank-and-file Republicans across America fear."

His email did not mention that House Speaker Paul Ryan, R-Wis., is expected to be presiding officer for much of the convention. Some opponents of Trump and Cruz have suggested that Ryan, his party's 2012 vice presidential candidate, would be a preferable presidential nominee this year, but Ryan has said he doesn't want to be tabbed.

In an email sent hours later, RNC chief counsel John Ryder said the controversial amendment would in fact be included among the items given priority consideration when party officials discuss convention rules this week in Florida.

But echoing the view of Priebus and some other Republicans on the party's rules committee, Ryder added, "Major changes now are dangerous and not a good idea, in my humble opinion."

Many Republican leaders have said party officials should not change current convention rules for fear of being accused by the competing presidential candidates of tilting the bylaws to influence the outcome.

They have noted that the final decisions on the rules will be made anyway by the convention's 2,472 delegates, probably on July 18, the gathering's first day.

When Republicans meet in Florida next week to discuss their rules, Oregon RNC committeeman Solomon Yue wants to propose not running full convention meetings under the rules of the House of Representatives. Instead, Yue wants to use Roberts Rules of Order.

Yue and others say under the Roberts rules, it would be easier for the convention's delegates to vote to block an effort by the convention's presiding officer to consider new nominees for president. Under House rules, the presiding officer has more power to make decisions about the proceedings.

Ash said RNC officials have repeatedly asked him and Yue to withdraw Yue's proposal or even to cancel this week's GOP rules committee meeting. Ash said he refused.

He said that last Thursday, Ryder "convened a rules committee whip call to strategize against and led the opposition to the Yue amendment at the chairman's request."

He said during that call, RNC officials acknowledged that Yue's amendment had been "pre-submitted" by a deadline that would give it priority treatment his week. But the next afternoon, Ash said, the RNC sent an email "incorrectly stating" that Yue's proposed amendment had not been submitted in time to be included in the agenda for next week's meeting. That would deprive it of priority consideration.

"In view of the above, I consider this to be a breach of our trust," Ash wrote.

He added, "In light of this breach and an apparent unwillingness to conduct a proper debate on the amendment, is it prudent for the RNC to continue to give the extraordinary power of the House rules to the presiding officer of the convention, as opposed to the more transparent, democratic and majoritarian rules in Roberts?"

Ryder wrote that party officials thought they were following Yue's desire to circulate his amendment to delegates early next week, even though Yue submitted his proposal in time for the earlier "pre-submission deadline."

"Of course we wouldn't have left out Mr. Yue's amendment from the notice if we thought he wanted it included," Ryder wrote.