Fall of 7% in premarket trading would wipe $70bn off firm’s value as market frets CEO’s foray into politics will distract from role

Shares in Tesla are heading for a sharp fall in the US as investors fear Elon Musk’s launch of a new political party will present further problems for the electric carmaker.

Tesla stock was down more than 7% in pre-market trading on Monday, threatening to wipe approximately $70bn (£51bn) off the company’s value when Wall Street opens.