The UK's music industry body is demanding that a service offering a workaround to access banned site The Pirate Bay is shut down by its owner.
Pirate Party UK, a political group, has set up a proxy that can be used to reach the piracy site even though it has been blocked by the UK courts. The British Phonographic Industry (BPI) has written to the party's leader Loz Kaye to request the proxy's removal.
Mr Kaye told the BBC his party was "seeking legal advice".
"We've been clear all along, the reasons for the proxy," Mr Kaye added. "It is a legitimate tool, for a legitimate political end."