Lord Myners told the BBC that shareholders who do not hold shares for the long term should have inferior rights as owners, arguing that "companies are too important" for big shareholders to trade in and out of them "willy nilly".
"We've lost sight of the fact that a share certificate - in fact we don't have them now, it's all recorded electronically - but a share certificate is a right and entitlement of ownership which carries with it certain responsibilities," Lord Myners added.
"It's not a piece of paper to be traded, to be bought and sold."
Peter Montagnon, of the Association of British Insurers, said Lord Myners was "absolutely right" to raise a "real point" about the danger of "ownerless companies being unaccountable".
