There were 19,608 complaints about addressed direct mail related to the charity sector in 2008, representing about three-quarters of all charity marketing complaints referred to the body. The figure could be higher, as complaints raised about the misuse of data in direct mail campaigns were listed separately.

"A lot of complaints around DM are about data complaint issues. They're often about list management," said a spokeswoman for the FRSB.

Even so, the direct mail complaints represented more than 50m mailings and so are only 0.04% of the total volume.

"It's one of the highest volumes of activity," said the spokeswoman. "It's still a very valuable method of fund-raising."

Conversely, unaddressed mail campaigns sparked complaints in the low hundreds, despite nearly 100m pieces being sent.

As a percentage of volume, events caused the most protest at 15.43% followed by telemarketing (0.07%) and signing up donors on the street (0.06%).

In total, the report took in 500m charity contacts made by its member organisations, and complaints represented just 0.005% of them.