Fitch Ratings is warning that a surge in populism and anti-establishment sentiment is pushing the world into an era of economic nationalism. It adds that will weigh on long-term global growth.

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In its outlook for 2017, the agency says increased trade protectionism and weaker migration flows would dampen growth in advanced economies. The one upside is short-term budgetary measures could provide a boost for next year.

Fitch has revised up its global growth forecasts for next year by 0.1 percentage point, largely on the back of a fiscal boost expected in the U.S.–following Donald Trump’s January inauguration as president.

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One downside risk, Fitch says, centres on whether the “populist surge” accentuates tensions in Europe. The ratings agnecy identifies Britain’s vote to leave the European Union and Trump’s election as acts of populism.