One person spent up to $13,500 funding the registration of as many as 90 Liberal members to attend a contentious reform convention this weekend, sparking accusations they are trying to "buy" the party.

The revelation comes amid accusations a group aligned with former prime minister Tony Abbott is trying to "stack" the event due to be held at Rosehill racecourse this weekend.

Fairfax Media revealed on Monday that the group, the Democratic Reform Movement, was paying for registrations of members to attend.

The group is backing a motion to be considered at the meeting put up by the Federal Electorate Conference in Mr Abbott's seat of Warringah to hand more power to Liberal party members in preselections of state and federal candidates.