David Cameron will hold talks with Barack Obama today to highlight the benefits for Britain of a free trade deal between the EU and the US.
The Prime Minister will argue that an agreement could be worth up to £10 billion a year to the economy.
Mr Cameron may also need to reassure the president about the UK's future within the grouping.
It comes as Cabinet ministers Michael Gove and Philip Hammond yesterday became the latest senior figures to indicate they would currently vote to leave the EU.
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