Gordon Brown has called for an “economic coalition of the willing” to respond to Donald Trump’s tariffs with coordinated economic policies, including a reduction of interest rates.The former prime minister also said it was a moment for the UK to go even further in renewing ties with the EU, suggesting it should mean “collaboration that is even more extensive than removing post-Brexit trade barriers”.His call comes as China announced new tariffs of 84% on imports of all US goods, in a move that sent stock markets falling further. Keir Starmer struck a downbeat tone on Wednesday at the prospect of reducing all new tariff barriers with the US.Brown, who remains close to the prime minister, said world leaders needed to step up their collective action, warning: “We are seeing a simultaneous breakdown in economic and geopolitical orders.”Writing in the Guardian, he said the world had to draw from experiences of the 2008 financial crash, including offering extended credit to firms, lowering i…