I know tax advisers like to avoid all sex scandal stories, so few of you will have noticed the Lord Browne episodes of the last week or so.

You'd be wrong to, of course, because there is an intriguing tax reason for looking more closely at them!

I was looking at the original Mail on Sunday pieces, which say that the inital legal proceedings were provoked by a suggestion from Lord Browne's former partner Jeff Chevalier that BP was thinking of moving abroad for tax reasons.

That is a pretty sensational claim, and rather leaves the threat of HSBC leaving in the shade. At the very least HSBC sounds like it ought to be based abroad given what its initials stand for. A company called British Petroleum leaving the country for tax reasons really would cause some rows.

The trick for BP would not, however, to be to decide to move abroad for tax reasons. It must be likely that it would be cheaper to do it elsewhere.

No, the trick is to how to do it to avoid reputational damage, by disguising it as some other move. Shell set up in The Hague through its 'restructuring', and Barclays looks set to pull off a similar move to Amsterdam if it can buy ABN (by no means a foregone conclusion). Holland is the destination of choice for holding companies for tax reasons, and anyone who can decide to settle there for 'business reasons' is sitting pretty.

Could BP pull off a similar move? It's unclear precisely how, but as with the Shell and Barclays cases, you're hardly aware such moves are happening until the deal is done. We can only wait and see.

More generally one might reflect that many have been speculating that the trickle of companies leaving the UK for tax reasons could become a flood. If you add in the possibility of private equity taking over FTSE giants and setting up offshore parents to structure the deal, you could say the flood is already happening before our eyes.