Hi FarneyMan,
Put youself in the position of the potential purchaser(s) of the business. They will be doing "due dilligence" before they buy the company. I think they (the buyers) are entiltled to ask for lists of employees and their names, qualifications, positions in the company and gender etc.
Under the data protection acts your company can't use the information for any other purpose than what it was gathered for. In this case your employer has asked you for the infomation and has told you how it will be used.
Is your concern that the information will be used for some other purpose?
If your concerns relate to the intentions of the buying company then as Clubman mentioned you are protected by the Transfer of Undertakings Leglislation.
Is yours a unionised compnay (or industry)? Under the ToUE leglislation the companies are obliged to communicate with employees or their representatives.
ajapale