New York (CNN Business) Leaked documents, provenance unknown, that seem to cast a political party in a negative light, appear online at a critical moment in an election campaign and are paraded in front of voters and the media by the party's rivals. Later, it emerges that a foreign government — an unfriendly one — may have had a role in the documents coming to light.

It's a scenario some Americans fear might play out during the 2020 election — it did happen here in 2016, after all — and it is a scenario that is playing out right now in the United Kingdom just days before the country, in the grips of a crisis over Brexit, votes in an election that may determine how and whether it separates from the European Union.

Jeremy Corbyn, the leader of Britain's opposition Labour Party, late last month presented the press with copies of British government documents that he said showed the United Kingdom's health service could be privatized as a result of a potential trade deal with the US negotiated under his rival, Prime Minister Boris Johnson. Johnson has denied that Britain's health system would be on the table for any trade negotiations.

A UK government spokesperson said in a statement that the government is looking "into the matter, with support from the National Cyber Security Centre (NCSC)."

The spokesperson did not comment on the authenticity of the documents, saying, " We do not comment on leaks, and it would be inappropriate to comment further."

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