Investment in Britain's car sector fell by more than 70 percent in the first half of the year due to concerns about a disorderly Brexit, an industry body said on Wednesday, warning that leaving the EU without an agreement was the "worst outcome".

The automotive industry, Britain's biggest exporter of goods which employs more than 800,000 people, is one of the most vociferous opponents of a no-deal Brexit, fearing additional tariffs and bureaucracy could halt production.

Investment fell to £90 million (roughly R1,550,130,322) in the first half of 2019 compared to £347.3 million (roughly R5,981,839,711) in the same period the year before and £647.4 million (roughly R11,150,429,160) in the first half of 2017, the Society of Motor Manufacturers and Traders (SMMT) said.

"The fear of no-deal is causing investors to sit on their hands," said chief executive Mike Hawes.

"The worst outcome would be no-deal. That's what they fear, that is why they're not investing."

Firms have also spent at least £330 million (roughly R5,683,976,113) on Brexit contingencies such as securing warehousing space and stockpiling parts in order to mitigate the impact of possible delays to the movement of models and components at ports.