The time is evidently not yet ripe for Rio Tinto's management to book its Nixon-in-China breakthrough visit to Beijing. Even if yesterday's warlike comments by a senior Chinese official about the "monopolistic" proposed joint venture between Rio and BHP Billiton don't carry much weight - and it is, as often, hard to tell - they are a fair indication of the temperature following Rio's split with Chinalco: still red-hot.

Where does this leave Chinalco as it decides what to do with its 12 per cent stake in the UK part of the dual-listed miner? It has three, perhaps four, options: dump the whole lot now; renounce its rights to new shares and allow itself to be diluted; take up its rights and sit tight; or gradually increase its holding.

There's no doubt Chinalco and its political masters are still smarting from Rio's decision to drop its planned venture with the state-controlled company in favour of the rights issue and a BHP tie-up. By selling up and flouncing off, the Chinese would be exercising the right of all jilted lovers to slam the door satisfyingly hard as they exit. But where would that leave them? Outside and out of pocket. Chinalco would arguably lose more face at home by crystallising its losses than it did when Rio dumped it.