The FTSE 100, the blue chip stock index, has reversed earlier gains and is now trading down 0.77% at 7,553.35.
Connor Campbell, financial analyst at Spreadex, says: "The FTSE was crushed under the weight of its sizeable commodity stocks on Wednesday, plunging towards 7,550 as chaos spread throughout the sector.
"With Brent Crude falling under $72 per barrel after slipping 1%, gold sliding to $1,192 an ounce and copper sinking around 2.5% to hit a fresh 13 month low, the FTSE’s oil and mining firms were not in a good way.
"BP and Shell both slipped 0.7%, the likes of Rio Tinto, Anglo American and Antofagasta were down anywhere between 2.5% and 4%, and Fresnillo shed 5.5%.
"All this led to the UK index itself dropping 70 points, testing intraday lows last seen at the start of the month."