Passengers flying to America from Britain could face strict searches and interrogations by Homeland Security staff at UK airports, after the British government showed an interest in entering into a "preclearance" agreement with the US.

Documents obtained by the Guardian show US authorities approached Britain and four other EU member states about setting up preclearance checks at European airports at two meetings of the European council's transatlantic relations working party (Cotra) in July.

According to the document – a German government response to a parliamentary question submitted by the Left party – Britain is the only country out of the five EU states to have expressly welcomed the proposal, stating that "Britain sees the advantages in allowing this procedure".