Churchill the legend exists in much printed material as well as in an abundance of sound and visual recordings, which is surely why he qualifies as a "national heritage". Does possession of the original documents add anything to this public perception of greatness? From the controversy generated, it would appear that most people do not think so. The issue, then, is what is meant by "national heritage".
When the lottery was set up, few people would have had any difficulty with, say, money being used to save Salisbury cathedral from falling down and to prevent it from being dismantled and rebuilt in the US. Photographs or film of the cathedral would not be adequate to preserve our heritage. But would the transfer of Churchill's papers elsewhere be comparable? It is what Churchill did and what he said - even how he said it - that is our heritage, not a bundle of papers.
G F Steele