WASHINGTON — The Democratic National Committee said Friday it would recommend exemptions to Iowa and Nevada that would allow them to avoid new guidelines requiring caucus states to allow remote participation without attending a caucus event. The waivers avert, for now, a showdown over voting rules between the committee and early caucus states.

The proposed waivers, which are expected to be approved by the party’s powerful rules and bylaws committee, come after D.N.C. leadership signaled it would block plans to allow some caucusgoers in Iowa and Nevada to vote by phone next year, bowing to security concerns about the process being hacked, according to four people with knowledge of the decision.

The committee’s announcement serves as a major setback to Democrats who have long hoped to expand the caucus-state electorate beyond those voters able to attend a winter-night gathering for several hours.

“People who believe in democracy and believe that people who are working or physically challenged should be able to participate are screwed by this decision,” said Larry Cohen, a D.N.C. member from Maryland who has long advocated allowing absentee participation in caucuses.