Sterling slumped close to a one-month low against the dollar Tuesday as investors fretted over heightened Brexit tensions ahead of crunch trade talks between London and Brussels. In midday deals, the pound dropped more than 1.0 percent versus the greenback to $1.3022 -- a level last seen on August 12 -- before edging back slightly. It also lost ground against the euro to extend a four-day losing streak. The pound began its fall Monday after Prime Minister Boris Johnson revived the prospect of a no-deal Brexit, saying if an EU trade deal is not struck by October 15 then there would not be one. On Wall Street, coming off a long Labor Day holiday weekend, US tech stocks took a battering, with Tesla slumping more than 15 percent while oil prices plunged more than six percent as the coronavirus pandemic weighed on the outlook for demand. About 10 minutes into trading, the Dow Jones Industrial Average was down 1.6 percent while the tech-rich Nasdaq Composite Index lost 3.0 percent for a third straight decline. Sterling fell on confirmation that the head of the UK government's legal department has resigned over Johnson's last-minute changes to Britain's EU Withdrawal Agreement. Northern Ireland Secretary Brandon Lewis admitted that the changes break international law in "tightly defined circumstances". The eighth round of negotiations resume this week, with both sides talking tough as the end of a transition period approaches. "It looks like the wheels of the Brexit bus are finally falling off, as news of the head of UK government legal (department) resigns," said analyst Sebastien Clements at international payments company OFX. "Whilst we should caution that this indicates disharmony, it is also possibly an overreaction by the market to a negative headline, and does not necessarily make a deal with the EU less likely than it was before," Markets.com analyst Neil Wilson added. Asian stocks had ticked higher following steep drops last week, as investors brushed off US President Donald Trump's latest anti-China salvo. Despite continued uncertainty about the timetable for economic recovery -- and with no Covid-19 vaccine yet available -- investors remain convinced central banks around the world are willing to play backstop and keep monetary policy supportive for years to come. Fitch Ratings meanwhile indicated it expected global GDP to fall by 4.4 percent in 2020, a small upward revision from the 4.6 decline forecast in June with China regaining its pre-virus level of GDP and US, French and British retail sales bouncing back. "But we doubt this will become the much-lauded 'V'-shaped recovery," Fitch warned in its latest Global Economic Outlook. Pound/dollar: DOWN at $1.3027 from $1.3166 at 2100 GMT Euro/pound: UP at 90.48 pence from 89.76 pence Euro/dollar: DOWN at $1.1784 from $1.1817 Dollar/yen: DOWN at 105.98 yen from 106.27 yen West Texas Intermediate: DOWN 6.7 percent at $37.12 per barrel Brent North Sea crude: DOWN 4.3 percent at $40.21 per barrel New York - Dow: DOWN 1.6 percent at 27,689.43 points London - FTSE 100: DOWN 1.1 percent at 5,873.73 points Frankfurt - DAX 30: DOWN 1.5 percent at 12,989.41 Paris - CAC 40: DOWN 2.0 percent at 4,951.10 EURO STOXX 50: DOWN 2.0 percent at 3,248.19 Tokyo - Nikkei 225: UP 0.8 percent at 23,274.13 (close) Hong Kong - Hang Seng: UP 0.1 percent at 24,624.34 (close) Shanghai - Composite: UP 0.7 percent at 3,316.42 (close) burs-rfj/cdw/wai