The chancellor will make the case for free trade as Labour is warned that it must choose between the United States and the European Union

The chancellor Rachel Reeves will use a keynote speech this week to promote free and open trade between nations as a cornerstone of UK economic policy, putting the Labour government on direct collision course with president-elect Donald Trump.

Reeves will use her first speech at the Mansion House – an annual showpiece for the chancellor – to outline a post-budget plan to “go for growth”. But as the UK government scrambles to respond to Trump’s emphatic victory, and the challenges it poses for Britain on vital issues of economic and foreign policy, the chancellor is expected to be clear that she will take the fight to Washington in defence of free trade.