Prime Minister Theresa May said on Tuesday it was important to set out the timing of Britain's exit from the European Union to reassure businesses after sterling plunged in the wake of her announcement of the deadline.
On Sunday May said she would trigger the formal 'Article 50' legal exit process by the end of March, at which point Britain and the EU would enter an initial two-year negotiating period.
The news sent sterling towards a three-decade low against the dollar on Monday while shares rose to a 16-month high.
"Businesses and people here in the UK want some degree of clarity as to when that timing is going to be," she told ITV's Good Morning Britain show. "I want to give people more certainty so we will see a much smoother process as we enter those negotiations."