Tesla's first-quarter sales slumped 13 per cent, its weakest performance in nearly three years, in a backlash to CEO Elon Musk's embrace of far-right politics and as consumers seek out newer models from rival electric-vehicle makers. Shares of the automaker fell about 6 per cent in early trading on Wednesday as the company recorded a bigger-than-expected drop in sales to 336,681 vehicles in the January-March period. A year ago, Tesla had delivered 386,810 units and this time the expectation was for 372,410 vehicles, according to an average estimate of 15 analysts from Visible Alpha.