Mrs May wants to clarify her plans before an European Union leaders' summit in June and to seal a deal on Britain's new relationship with the European Union in October, less than six months before Brexit.
Sterling tumbled against the euro, dollar yen and Swiss franc.
Sterling and United Kingdom government bonds will fall further in the run-up to Brexit, even after the pound slumped this week to its lowest in nearly a year, prominent Brexit-supporting British hedge fund manager Crispin Odey said on Thursday.
Warnings this month from Bank of England Governor Mark Carney and trade minister Liam Fox, that the prospect of a no-deal Brexit was growing, triggered the recent slide.
Three-month sterling implied volatility, a gauge of expected swings in a currency, surged to its highest since March.
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After an initial uptick to 1.2960 level, the GBP/USD pair met with some fresh supply and dropped to fresh eleven-month lows in the last hour.
Sterling is trading down 0.7 percent in the middle of 1.2800s against the US Dollar after the news of the United Kingdom government readying the meeting for mid-September to prepare plans for a no-deal Brexit scenario.
The BoE raised rates from crisis-era lows last week, but few investors saw the increase as a vote of confidence in the economy with so much political uncertainty ahead. "The next move could be a cut rather than another hike".
While most of the blame for the pound's tumble has been put squarely on fears of the United Kingdom crashing out of the European Union without a deal, analysts have been keen to point out that August has always been a hard month for the currency.
"We remain bearish on the pound in the short term until the Brexit mess is out the way and look for the currency to enter a $1.27-1.28 range before the leaders' summit in September", said Nomura strategist Jordan Rochester. That indicates a sharp rise in demand for sterling "puts", or options to sell the currency.
Traders are now preparing for Friday's reading of second-quarter British economic growth numbers to give the pound some possible relief.