In April 2018, Trevelyan was criticised by the Alnwick Labour Party in the wake of the Poisoning of Sergei and Yulia Skripal over claims that a Russian businessman gave almost £50,000 to fund her 2015 general election campaign. The Labour Party questioned why the Conservative Party was accepting large donations from such sources. Trevelyan stated that the man in question was now a British citizen who had invested significantly in the region, while she had personally not received any funds from Alexander Temerko, with funds going to the Berwick-upon-Tweed Conservative Association.