With talks with the European Union seemingly deadlocked, and the March exit date looming closer, the BCC found that many firms were still awaiting clarity from the government or had stopped paying attention to events. The inaction is most acute among small businesses, it said.

The findings come as a separate report from GfK Friday showed that UK consumer confidence dropped in September as uncertainty surrounding Britain’s exit from the EU continued to damage sentiment.

“Too many businesses across the UK are still not ready for Brexit,” said Adam Marshall, director general of the BCC. “With six months to go until the UK’s planned departure, firms still don’t have answers from government to the most basic questions about future trading conditions.”

The Brexit negotiations are reaching a crucial phase with seven weeks to go before a mid-November deadline. A lack of progress has raised concerns about the risk of a no-deal, prompting governments on both sides to step up their preparations for the UK crashing out of the bloc.

Optimism among companies had swelled before this month’s summit in Salzburg. A report by Lloyds showed business confidence rebounded from an August drop, though the survey was done before Prime Minister Theresa May returned from the meeting where European leaders rejected her latest plan.

The BCC’s survey showed showed that about one-fifth British firms would cut investment if the UK leaves without new trading arrangements, with large and internationally active companies most exposed.

Around the same proportion would move part or all of their business to the EU, according to the report, which called on the government secure a deal and ensure a transition period.