Certainty level: 90%
Dimbleby interviews John Major during the election campaign. Here is the exchange, regarding Neil Hamilton, the "sleazy" Tory candidate;
Dimbleby: "It's a direct quotation from what he said to Sir Gordon Downey and what he said to his local newspaper, the Knutsford Guardian". Major: "Well, heaven forfend that I should doubt what the Knutsford Guardian actually said" Dimbleby: "Well I should hope so" Major: "Absolutely, it would be quite unforgivable to doubt the Knutsford Guardian"
What I find in this segment is an assonance between "Knutsford" and "Nut" or "Nuts". I think Dimbleby deliberately invents the play on words, and says it clearly enough for Major to pick it up and repeat it. You can gauge Dimbleby's intent from his facial expression of false honesty when he uses the words "Knutsford Guardian"; and Major's reaction follows from his recognition of Dimbleby's intent; Major smiles and says it would be "unforgivable to doubt the Knutsford Guardian". These are much clearer on the original video than on this Quicktime clip.