A parliamentary committee on Wednesday accused former prime minister David Cameron's government of "gross negligence" for failing to prepare for a possible vote to leave the European Union before last month's referendum.
"The previous government's considered view not to instruct key departments, including the [Foreign Office], to plan for the possibility that the electorate would vote to leave the EU amounted to gross negligence," the cross-party parliamentary foreign affairs committee said in a report.
It said the lack of planning had "exacerbated post-referendum uncertainty both within the UK and amongst key international partners" and made the work of new Prime Minister Theresa May "substantially more difficult."
"The lack of contingency planning inevitably means that the government's plans are tentative and just emerging," the report said.
Lawmaker Crispin Blunt, who chairs the committee, said the new government "needs to give clear signals" to Britain's "allies across the world" that Britain is "determined" to assert its place in the world post Brexit.
"This is not just about trade in the EU or with the rest of the world – although that represents a significant challenge," Blunt said. "This is also about the UK's international reputation."
Cameron resigned after he failed in his campaign to convince a majority to vote against Brexit and stay in the 28-member political bloc.