Some people have followed Frank Field's advice and asked the Information Commissioner whether the Data Protection Act prevents trustees from revealing information about members of their pension scheme to pensioners' associations.
Here is the COPAS Council's interpretation of the answers.
a) The Act does not prevent the trustees from revealing the names of those members who have died. (The Act applies only to the information on the living)
b) It does't prevent the trustees from telling the members that your organisation exists. (That is not releasing personal data)
c) It does prevent the trustees giving out the addresses, if they don't have (implicit or explicit) permission from the addressees. Such permission could take the form of implied permission when the address was originally collected - that the addressee understood that possibly giving his/her address to a pensioners' association was part of the reason for which the address was being collected. The Information Commissioner suggests that this is not the usual case.
The permission could be sought from the addressees. This could be opt-out, ie "Tell us if you don't want your address given to the association", but even then there would be a cost in keeping a record of those who opted out. The trustees might argue that the cost was not justified.
At least one trust (Philips) has provided its association with the list, so it can be done. Overall it is likely to come down to the attitude of the trustees. If they are keen for the retirees to be well informed, then they will find a way by which the association can write to potential members. If they are not keen, they can use the Data Protection Act as part of an argument for not releasing address of living retirees.