[twic]

This doesn't seem insuperable. The rule could be that any dividend paid to anyone other than a UK taxpayer, or another UK company, is taxed at the top rate of income tax. That would make such a shunt pointless.

You could then extend the existing international double taxation agreements to cover these dividends. So, for example, if a dividend is paid to a Dutch taxpayer, it is not taxed at source, but as income. You might want to retain the current UK arrangement in this situation, though, so as to keep some of that tax revenue in the UK. You wouldn't extend these arrangements to tax havens.

Manoeuvres like the Double Irish or whatever would still get around this, and would still need to be attacked in the way they are (or at least should be) now.

You would need to extend the spirit of this rule to share repurchases, which might be tricky.