The pound plunged 6.1% to a fresh 31-year low against the dollar on Friday morning, its latest slump after Britain firmed up details on the timing of its exit from the European Union.

Britain's currency dropped to $1.1841 shortly after 8:00 am (2300 GMT on Thursday) in Tokyo trade, compared with $1.2614 in New York late Thursday, before rebounding to around $1.2450.