Hugh Miller's cottage is one of those earmarked for closure
A dissatisfied group of National Trust for Scotland (NTS) members has launched a campaign to force an extraordinary general meeting of the trust.
They said plans to close properties for financial reasons had been made without consultation of the trust's 300,000 members.
The group, which called itself In Trust for Scotland (ITFS), has launched a website to support its cause.
NTS said it was fully accountable to its membership.
Bill Fraser of ITFS said he was confident of encouraging 2,000 NTS members to fill in support forms to force an EGM to "hold the board and council to account".
He said: 'To avoid being presented with a fait accompli at September's AGM, an extraordinary general meeting must be called before the board and council causes any more harm to the NTS.
"The incredible decision by the NTS board and council to close 11 properties must be properly debated by the worldwide membership.
"The views of members have been ignored by an undemocratic board and an unwieldy council which includes representatives from many well-known Scottish organisations.
"Who will dare to leave treasures or legacies in the future to a board and council which ignore their core responsibility of 'in trust for the nation'?"
A spokesman for NTS said it was in consultation with its staff and stakeholders, including central and local government representatives, regarding the future use of the 11 properties.
He added: "We are pleased with the constructive nature of these discussions to date.
"At a meeting of the trust's council on 27 March, the board explained the rationale for its proposals, which the council fully endorsed.
"As council is the governing body of the trust, comprised of elected members of the organisation, the Board has already fulfilled its duty to account to the membership.
"At each AGM, the membership has the opportunity to appoint new members to the council."