UKIP has appealed against a notice from a data watchdog compelling it to hand over information or face criminal sanctions.
The Information Commissioner's Office issued the notice to UKIP as part of "a formal investigation into the use of data analytics for political purposes" with a particular focus on the EU referendum.
Its investigation includes companies such as Cambridge Analytica and AggregateIQ, as well as social media platforms, which may have fallen foul of data protection laws.
In an update on the investigation, commissioner Elizabeth Denham said her office had issued four notices requesting organisations to hand over information regarding their use of data analytics.
A spokesperson for UKIP told Sky News: "We're perfectly happy to work with the ICO, we're appealing the legal threat made against us."
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They added that it was not clear why UKIP had been the only organisation named by the ICO.
An ICO spokesperson explained that the party was the only organisation to appeal and in doing so it added its name to the tribunal's public records.