Canadian charities would have to turn over lists of their donors' identities to the Canada Revenue Agency under a proposal being floated by the Conservative government.

The move is touted as a way to prevent tax-receipt fraud, but some charities are wary of the administrative burden — and the potential close surveillance of groups that criticize government policies.

Revenue Minister Kerry-Lynne Findlay made the suggestion behind closed doors this spring to charities officials in Ottawa as the government seeks ways to tighten regulation of Canada's charitable sector.

Findlay asked officials of the Heart and Stroke Foundation, the Canadian Cancer Society and others for their input, as well as their reaction to a proposal to standardize the format, size and colour of official income-tax receipts for charitable donations.

The consultation took place before a March 26 media event at which Findlay and Kevin Sorenson, minister of state for finance, boasted about the government's achievements in reducing red tape for charities.

The suggestion about turning over donor lists also came as some charities, subject to lengthy audits by the Canada Revenue Agency over their political activities, were feeling vulnerable and threatened by the Harper government.