With all due respect to the BBC, the imposition of such a “one-time” wealth tax would have a disastrous impact on the British economy.
Capital flight would occur, much like what is happening already in Argentina (which brought in such a measure last week).
Given the now noticeable shift in public discourse in favour of greater burdens being placed on successful business people, those with means should start thinking about reorganising their affairs. Second citizenship and permanent residency verticals are part of the tax solution.