The U.S. Supreme Court has ruled that Donald Trump’s global tariffs imposed unilaterally by excercising his emergency powers, were illegal.

That includes his so-called reciprocal tariffs levied against a number of countries.

The ruling affects the 10 per cent tariff the U.S. has imposed on other countries and additional punitive levies on Canada and a number of other countries and trading partners, including Mexico, the EU, and China among others.

The Supreme Court’s 6-3 decision has dealt Trump’s contentious economic policy a blow, but his administration could still impose tariffs under other laws.