Gordon Brown should copy HKMA

Given that the equity market is the most liquid, the most talked about and a key element in economic Lead Indicators, why doesn't HMG buy bank shares?
It can then make proper representation as a shareholder in the control of the business and can profit from its involvement.
Given that it is giving liquidity through the Bank of England, some equity upside is not too much to ask.
Unlike Mr Buffet, HMG should buy from the market and not take options on future performance. Furthermore, the preference share route is best avoided; these do not provide a cushion to a bank's equity price, but act as a penal charge on income. In the current environment of liability guarantees, the cushion to unsecured creditors afforded by the preference shares is simply not needed.
The common equity purchase plus judicious involvement in any rights issues or placings represent the best spur for confidence and allow the market to see the floor. All those investors now holding cash can then take a view.
In purchasing the equity, the trading criteria should be specific; e.g. it will be a potential buyer of bank shares if the price to book is say less than 0.35x and a potential seller if the price to book is over 0.65x. It will never sell more than 5% of its holding or 1% of the shares outstanding in the bank in any one day, and so on.
Does it work? Ask the Hong Kong Monetary Authority if their $15bn of share purchases on the Hong Kong stockmarket, over two weeks in August 1998, worked. I think it did, and they subsquently made a good profit. Perhaps there's some gecko lurking somewhere in Gordon waiting to emerge.