The costs of Brexit are already mounting before the U.K. has even left the European Union, the country’s biggest business lobby group said.

“There is the direct cost of what businesses are having to put into their businesses and their supply chains to protect themselves” from the impact of Brexit, Carolyn Fairbairn, director-general of the Confederation of British Industry, said in an interview at the Conservative Party Conference in Birmingham. “The other cost, which is less easy to see, is the investment that hasn’t happened as a result of Brexit uncertainty.”

There’s also a danger that Brexit sucks the energy of government away from big domestic priorities such as infrastructure, digital connectivity and training, according to Fairbairn’s counterpart at the British Chambers of Commerce, Adam Marshall. The government must focus on another runway at London’s Heathrow airport and push ahead with projects to build high-speed rail and improve broadband and mobile connectivity, he said.

“The biggest risk to the future of the United Kingdom is that we stagger exhausted over the Brexit finish line, but we haven’t put in place the steps to ensure that we’re competitive here at home,’’ Marshall said in an interview. He called on Chancellor of the Exchequer Philip Hammond to be “radical” in his budget, due at the end of the month, to ensure he attracts business investment.

‘Serious Questions’

“Investors in boardrooms across the world asking very serious questions about whether the U.K. is a place where they can reliably place their money,” Marshall said. Hammond “should be trying to help those companies who are wavering here at home, or those companies overseas who are considering their position, to crowd all of them in and get them to commit to those investments in the United Kingdom.’’

The calls by the business chiefs reflect how corporate Britain is increasingly concerned about the slow progress in Brexit negotiations and domestic policy inertia that’s damping growth.

While the CBI hasn’t put a figure on Brexit costs so far, Fairbairn said it certainly runs to billions of pounds. Plenty of companies have already gone public, though; U.S. drugs giant Pfizer Inc. said last month its costs will reach $100 million, while GlaxoSmithKline Plc predicts a similar financial hit. On Tuesday, Toyota Motor Corp. warned that a hard Brexit would hurt revenue.

Fairbairn said Brexit-related uncertainty is already feeding through to U.K. growth because it has dimmed business investment. The U.K. has gone from being the fastest-growing economy in the Group of Seven nations before the Brexit vote, to being one of the slowest.

Damping Investment

“Business investment growth is running in the low single digits,” she said. “Given the scale of international growth, there’s a strong global market, we should be expecting to see double-digit business investment growth.”

While the U.K.’s biggest companies have done their contingency planning for Brexit already, they’ve spent “a lot of money,” which is “wasted investment that could have gone into R&D,” Fairbairn said. Medium-sized businesses “are just beginning to prepare now, and they really are saying we do not have enough time,” she added.

Only one in seven smaller companies have even begun to prepare, with many not realizing how Brexit might affect them, their supply chains, or their customers, she said.

Fairbairn said that while the future trade relationship with the EU is important, the priority for business is for Prime Minister Theresa May to secure the EU withdrawal deal, because that will unlock a planned 21-month transition period that gives companies more breathing space.

“Yes there must be conversations around the final trade agreement, but we’re not going to get to that if we haven’t negotiated the divorce settlement,’’ she said.