On Wednesday, the UK informed Spain it would take "no further action [...] at this time" on the arrest warrant it had been sent for former Catalan minister Clara Ponsatí. In the original letter, sent through the Schengen SIRENE system, it described the warrant as "disproportionate".
The UK later sent a second message retracting that description and restating its position that if provided with additional information on the case it would reconsider its decision. Spanish foreign minister Josep Borrell, who on 1st December will take over as EU high representative for foreign affairs, sent a tweet, which he later deleted, saying that "the British police has corrected its use of the term disproportionate to describe the extradition request for Ponsatí". In that tweet, he included a screen capture of the second document.
Some in Spain, including the political party ERC, criticised his publication of what they say is a confidential and restricted document. In a letter to the European Commission's incoming president, Ursula von der Leyen, MEP Diana Riba (ERC) called for an "urgent investigation" into the "extremely worrisome and unacceptable behaviour".
In today's midday press briefing, European Commission spokesperson Mina Andreeva was asked about the controversy. "There are very clear rules in place regarding access to and use of the Schengen information system", she said, adding that they expect all member states to "respect the letter and spirit of these rules, notably any confidentiality requirements."
That said, she argued that it is now a "matter for the responsible national authorities to look into" and that "it's not possible [for the Commission] to speculate further at this stage".