When the Trump administration last Friday announced a $50bn list of Chinese imports targeted for tariffs, it stressed that it excluded “goods commonly purchased by American consumers such as cellular telephones or televisions”.

But as Donald Trump escalates his trade spat with Beijing by threatening tariffs on a further $200bn in Chinese imports and pursues possible auto tariffs, it is a pledge the US president is likely to struggle to repeat, due to looming economic and political tests.

In the already imposed global steel and aluminium tariffs and the China lists it has unveiled so far, the Trump administration has largely focused on raw materials and components. Its target has been supply chains, and the impact upon US consumers has been indirect.