Polly Toynbee's article in today's Guardian lets another Tescos tax story out of the bag:

Since Tesco has murmured to other newspapers that it may sue the Guardian, to warn others against following our story - though no writ has arrived - let's stress that these low-tax paying habits are all very, very legal, all arranged by highly paid lawyers from highly respected world-beating City law firms. They set the seal on avoidance not just as OK, but as a good or even as a necessary business practice. (Incidentally, humbler Morrisons pays proportionately much more tax than Tesco). Vince Cable, the Liberal Democrat shadow chancellor, looking down this list of underpaying companies, is now asking why.

I admit I guessed as much when writing my blog on this issue on Wednesday. I knew that this story was in the offing last October. I suspected that the delay could only be explained by Tescos legal department and Polly has effectively confirmed that to be true.

It's an interesting idea that Tescos says it has:

a duty to organise its affairs in a tax-efficient manner

and yet threatens to sue anyone who talks about it doing so.

What are they ashamed of? How come doing your duty must not be spoken about? Could it be that they're not quite sure of their ground here? Maybe, just maybe, they're a little ashamed of what they're doing?

Give us the answer Tescos.