Calls grew for Prime Minister Theresa May to outline plans for her Brexit negotiating strategy on Thursday, after a think tank warned that her "silence" was confusing for other EU nations and unsettling for businesses operating in Britain.
There has been "a gaping void of information" about how the government plans to move forward following June's vote for Britain to leave the European Union, the Institute for Government said in a report.
"The prime minister's silence about how she intends to reach an initial negotiating position is proving problematic," the think tank said, urging her government to "move swiftly to spell out its plan."
Former Conservative cabinet minister Nicky Morgan, who campaigned against Brexit, urged May to give at least a "broad outline" of her negotiating plan.
"There does need to be a clear plan from the top of government about what it is that we are looking for," Morgan told BBC Radio 4's Today programme.
"The longer that gap is left, the more likely it is that - as we are beginning to see - people are taking up positions, whether it's 'hard' Brexit or 'soft' Brexit," Morgan said, referring to a Brexit outside or inside the single market.
"There is a danger that we will start finding ourselves, or the government will find itself, in a position where other people are setting the terms of the debate," she said.
Veteran Conservative lawmaker Ken Clarke, another pro-EU former cabinet minister, told the New Statesman magazine that "nobody in the government has the first idea of what they're going to do next on the Brexit front."
Morgan said balancing access to the European single market with controls on EU migration would be "at the heart" of the Brexit negotiations.
But Italian Prime Minister Matteo Renzi told the BBC that it would be "impossible to give British people more rights than the other people outside the EU."
Renzi urged May to trigger Article 50 of the Lisbon Treaty - which sets the rules for a two-year negotiating process for a nation leaving the EU - as soon as possible.
The Institute for Government said planning for Brexit could cost the government some 65 million pounds (85 million dollars) annually and require hiring an extra 500 civil servants.
"Silence is not a strategy," said Hannah White, co-author of the report.
"The current situation - where we are left to interpret personal musings of individual ministers - is frustrating those looking for an early exit, perplexing those with whom we have to negotiate and unsettling those looking to do business in the UK," White said.
"The prime minister has sworn she will not give a running commentary on negotiations, but she needs rapidly to clarify how and when the government intends to go about making decisions on Brexit," she said.