Investing.com
The currency is down by 0.9% at 1.2864 against the dollar as of 7:48 a.m. ET.
On Sunday, Prime Minister Theresa May said the UK will trigger Article 50 - aka the process of separating the UK from the EU - before the end of March 2017.
"Sterling has a bad case of the Monday blues," Marc Chandler, the global head of currency strategy at Brown Brothers Harriman, wrote earlier.
As for the rest of the world, here's the scoreboard as of 7:48 a.m. ET:
- The Russian ruble hit its highest level against the dollar since October 2015, touching 62.2216 around 6:30 a.m. ET. It has back-tracked slightly since then, and is up 0.8% at 62.3599 per dollar. Brent crude oil is trading above $50 a barrel. Notably, when the ruble had strengthened back in July, Vladimir Putin drew attention to the currency's appreciation.
- The US dollar index is little changed at 95.52 ahead of a heavy data day. Markit manufacturing PMI will be released at 9:45 a.m. ET, while construction spending and ISM manufacturing are both due out at 10 a.m. ET.
- The Japanese yen is little changed at 101.39 per dollar after Japan's Tankan Larger Manfaucturers Index came in at 6 for the third quarter, below expectations of 7, while the Tankan Large Non-Manufacturers Index came in at 18, as expected.
- The Chinese yuan was officially added to the IMF's SDR basket on Saturday.
- The Mexican peso is up by 0.9% at 19.2184 per dollar.
- The euro is little changed at 1.1235 against the dollar.