Britain must keep an "open mind" about Donald Trump's economic policies, Labour's deputy leader will insist as he suggests protectionist reforms could put workers first instead of the ruling elite.
Brexit will free up the Government to favour British goods and allow the UK to hit back against the new president's "buy American" pledge, Tom Watson will say.
In a speech to the Co-operative Party Economic Conference in London, he will suggest the shock EU referendum and US election results are changing attitudes to free trade.
The deputy leader will highlight how the international trading agreements Mr Trump is ripping up have also been opposed by unions because they stop countries from protecting workers.
Attacking the "chattering classes" for their "sneering derision" over calls to buy British, he will insist significant opportunities to boost business will be opened up when the country is no longer bound by European Union red tape.
He will say investment in industries where the country currently relies heavily on imports could give British manufacturers a "Brexit bounce".
Mr Watson is expected to say: "If Trump says buys American, our rational response is Buy British.
"Yet to say 'Buy British' these days risks sneering derision from much of Britain's commentariat and chattering classes, few of whom of been on a factory floor lately. When did you last hear Theresa May say it?" he will say.
"It is an age old bugbear of many politicians that the UK's strict adherence to EU procurement rules is observed more keenly in London than in Rome and Paris.
"That era is about to end. The opportunities in public sector procurement to purchase British made goods and services are significant."
Labour is in turmoil over its approach to Brexit, with leader Jeremy Corbyn facing a growing rebellion after ordering his MPs to back legislation triggering Article 50.
Shadow Welsh secretary Jo Stevens and shadow education minister Tulip Siddiq have both quit in protest and others are expected to follow.
Mr Watson will, however, focus on the benefits that quitting the bloc can have for industry and workers.
He will add: "The election of Donald Trump adds real uncertainty to global trading trading arrangements, against a backdrop of significantly increased economic nationalism," he will say.
"The basic assumptions that underpin current global policy, most importantly the assumption that free trade is good, and protectionism bad, are changing with Trump's election, and with Brexit.
"For the UK, it is imperative we keep an open mind about the Trump administration's economic policy and ambitions.
"Political and business leaders, and trade unions, need to ask themselves this: What if he does bring back the manufacturing jobs back to America?
"What if the interests of the rustbelt workers, who had their lives turned upside down by cheap imports from China, are prioritised over the ideological beliefs of Davos habitues?
"Conventional economic orthodoxy says that free trade benefits all countries, if not all workers in those countries. Yet is this really true?
"You can make a cogent case that the debt fuelled growth of China has given Chinese corporations who receive forms of hidden state subsidies an unfair advantage in Western markets. Indeed Trump used the export of manufacturing jobs to China as a devastating political weapon.
"Now those international trade agreements Donald Trump is ripping up with gusto have also been the focus of opposition by organised labour, and for good reason: they also prohibit states from protecting workers.
"For the UK to ignore the early signs of a global reformation of international trading arrangements would be a mistake. For one, if there is to be a benefit to Brexit, many gains can be seen in domestic procurement."