EU officials have accused the British government of threatening to weaken security cooperation with the bloc unless the UK gets an equivalent to a major crime-fighting database. The UK is set to lose access to the Schengen Information System (SIS II), a massive EU database, where police across the continent share millions of pieces of information on criminal suspects, at the end of the year. The EU has said it is legally impossible for non-EU countries not respecting free movement of people to access the database and has proposed more basic information sharing. In the latest round of Brexit talks, UK negotiators told their EU counterparts that the offer wasn’t good enough. According to EU sources, the UK government threatened to walk away from information sharing if it could not have an equivalent to the SIS II database, which is used by British police every day. “The UK basically said it was not interested in what the EU suggested and that if they can’t have it then they would rather have nothing. So they are playing hardball,” said one EU official. “We have opened discussions on this,” said a second EU source. “They were not interested in anything that does not replicate the benefits of SIS II.” A UK government source described the EU account as “highly misleading” but did not deny rejecting the lesser offer. “What we are seeking is a future internal security agreement with the EU which provides capabilities similar to those delivered by SIS II, but I’m afraid the EU’s alternative proposals on data sharing are nowhere near reminiscent of this and are of limited operational value,” the source said. The Schengen Information System was created in 1995 by countries that had abolished internal border controls. In 2015 Theresa May, who was then the home secretary, took the UK into the database, securing an unprecedented special deal for a country outside the EU passport-free travel zone. During the EU referendum campaign experts warned Brexit imperilled access to the database and would damage the UK’s ability to fight terrorism and crime. British police and border guards are the third heaviest users of the database, making 571m searches in 2019 (a figure that includes automated bulk data sweeps) to look for wanted people or stolen goods. UK forces issued 36,680 alerts on people and 259,824 on vehicles in 2019 – essentially a request to other police to carry out checks. The government wants a system with “capabilities similar to those delivered by SIS II” meaning access to real-time data on tens of thousands of people. The EU offer, it argues, would add nothing to the UK’s law enforcement capability. EU negotiators want to maintain police data sharing with the UK, but say their hands are tied because of case law from the European court of justice (ECJ) that limits what can be offered to an outsider. European diplomats also cite political factors such the UK’s refusal to countenance a role for the ECJ and opposition to any reference to the European court of human rights (ECHR) in the EU-UK treaty. Both institutions are seen by European governments as providing crucial safeguards over the transfer of data or – in the case of the European arrest warrant – people. “We wanted of course to have an exchange of data, but it cannot be SIS as such,” an EU diplomat said, citing the absence of guarantees on the ECJ and ECHR. The Brexit clash comes after a prominent MEP accused the UK government of “behaving like cowboys” earlier this year, after a leaked EU report concluded that British authorities had illegally copied SIS II data. The report fuelled complaints that the UK wants the benefits of EU systems without offering reciprocal aid – a charge strongly rejected by the government. In 2018 the UK responded to 7,000 alerts put on the SIS II system by other countries, while it issued more than 22,500 alerts that led to responses around the EU.