Miners were hit by the uncertainty as the FTSE 100 Index slipped by a single point to 5768.6 and Japan's Nikkei 225 index fell nearly 1% at the close.
Anglo American was 27.75p lower at 1838.25p and Eurasian Natural Resources dipped 3.5p to 286.5p, while Xstrata was 13.95p lower at 956.35p.
On the risers board, Confused.com owner Admiral recovered from recent share price weakness to climb 29p to 1083p, a rise of 3%.
Outside the top flight, the focus was on the housebuilding sector after updates from the sector's biggest players.
Bovis Homes fared well, lifting 2% after it said it remained on track to report a strong increase in revenues in 2012. Its operating margin is also set to be around 13%, compared with 11% a year earlier, as firms such as Bovis benefit from building homes on land bought after the credit crunch.
Bovis shares were 4p higher at 519.5p, while Taylor Wimpey and Redrow were both flat at 58.95p and 158.7p respectively after announcing steady trading performances.