Chelsea and Portman building societies have thrown out resolutions from carpetbaggers aimed at triggering windfalls for members.
Chelsea, the UK's seventh-biggest society, last week dismissed a conversion resolution from Andrew Naughton-Doe following legal advice that it fell foul of the society's rules.
In a statement, Chelsea chairman Tim Barry said the resolution was invalid because persistent attempts to force it to demutualise interfered with the board's ability to properly manage the affairs of the society.
He said the board remained firm in the view that members' interests are best served by mutuality and there was no reason for the society to convert.
Portman has rejected six resolutions aiming to make it easier to force the society to convert because they did not have enough support.
The UK's fourth-biggest society said analysis by independent electoral scrutineers found that the number of valid members supporting the resolutions fell short of the 500 required.
Carpetbagger Tim Tanner is sending Portman an additional 200 resolution forms and is understood to be considering taking legal action against the decision.