Mr Diamond said: "The Conservative Party functions on integrity; not by manipulations. It is important that the rights of the membership on the United Kingdom's relationship with the European Union are respected.
"MPs remain accountable to their associations and the legal fund will ensure the independence of associations; and that the relationship between the membership and the MP remains unaffected by any gerrymandering."
One Brexit-supporting Tory donor said: "The Conservative Party has been infiltrated by Lib Dems for too long. It is time for a serious shake-up."
