Thompson defends Gaza appeal ad ban but says "valid" to link to it via BBC website

BBC director-general Mark Thompson has defended his decision not to allow the DEC Gaza appeal to be broadcast, in a letter to The Guardian today.
He describes yesterday's leader in The Guardian about the affair as "wholly misguided" and refutes claims that it is "inconsistent" to publish links to the DEC appeal on the BBC website.
Thompson says: "This is a valid decision for news editors to make when reporting that the appeal is happening; as we know that many people will want more information about the appeal or donating to it. Providing them with that information in no way alters the fact that my decision - however controversial - was the correct one to preserve the BBC's impartiality."