Banks, who grumble about the growing financial influence and preferential tax treatment of the credit union movement, may be tempted to point the finger at this week's US Supreme Court ruling limiting credit unions to members of a single organisation sharing a common purpose. The court declared that a move by the National Credit Union Administration (NCUA), the umbrella body for the movement, to expand its membership beyond a core unit in a single company or organisation was illegal.

US banks take the view that the movement, which began as low-key co-operatives providing mutual financial support, has evolved into highly specialised financial hybrids, functionally indistinguishable from the banks, yet continuing to receive special tax treatment and unfair legislative protection. Many credit unions are said to be "playing fast and lose with membership rules" and have "enjoyed a free ride at the expense of taxpayers". A familiar grumble which produced an equally familiar response from the credit unions. The NCUA criticised the decision to restrict the spread of its membership base as essentially undemocratic and says it will fight its corner in Congress, arguing that the movement provides an essential, affordable alternative to expensive, profit-driven banks. Be that as it may, now is perhaps not the best time for banks to draw Minister McCreeevy's attention to the ruling of the US court.