London, Sep 29 (IANS): The British Prime Minister's silence on her Brexit plans was causing problems and costing the country money, said a report published on Thursday.

The report by the Institute for Government think-tank criticised Theresa May for her silence on the position she intends to adopt in negotiations with the European Union (EU), which companies and other countries find worrying, EFE news reported.

Planning the UK's departure from the EU could cost the British government an annual 65 million pounds ($84.5 million) and would require 500 new people to be hired, said the report.

"In the short term, May needs, at the very least, to clarify the process and timescales through which she intends her government to agree to the UK's initial negotiating position," the report said.

The report said there were fears that May's decision to give three government departments (Foreign Affairs, International Commerce and Brexit) the responsibility to negotiate the exit would create a feeling of incoherence in the British government.

"This triple departmental structure risks creating fragmentation and incoherence, and a lack of clarity about the roles and responsibilities of the new departments has caused distractions and delayed work on Brexit," it said.

The UK voted to exit the EU in a referendum on June 23.