Armed counter-terrorism officers will be deployed on British cross-Channel ferries for the first time this summer, though government sources said there was no specific threat to passenger vessels. Firearms police from the Civil Nuclear Constabulary (CNC) are to be posted on ferries out of Dover, as well as on passenger ships between Newcastle and the Netherlands. The move will tighten security on British ferries, which are unguarded and seen as vulnerable, with passengers not individually searched or given body scans when boarding, unlike those on planes or Eurostar trains. A government spokesperson said: “The government will always take the strongest possible action to protect our national security and our priority remains maintaining the safety and security of our citizens. “We are constantly developing protection for UK citizens against the threat of terrorism. This includes strengthening security by fully equipping law enforcement and emergency responders to respond to terrorist incidents, no matter where they occur.” It is understood about 40 CNC officers will be posted on a rotation basis on ferries with a trial starting in July. The CNC has officers available as a result of nuclear power stations being decommissioned. A senior counter-terrorism source told the Times that ferries were seen as extremely vulnerable and “completely unguarded”. “Ferries are the weak link when it comes to policing transport against terror attacks. Moving a handful of CNC officers to ferries makes sense and they will be a visible deterrent,” the source said. A government source confirmed to the Guardian there was “no specific threat to passenger vessels” and the treaty and other cooperation with France formed part of the UK government’s wider strategy to ensure it was able to protect UK citizens against terrorism “no matter where it occurs”. With the decommissioning of nuclear power stations, the number of officers required to protect them is falling. The decision to redeploy CNC officers is part of a plan to extend the force’s remit to enable them to offer services beyond the civil nuclear sector and provide support to other police forces. A UK-France maritime security treaty was signed in July to improve joint working. It will come into force once the UK and France have completed ratification procedures and is designed to mitigate against a high-threat security incident on a ferry or other large vessel in the Channel. The treaty includes provisions that would enable the UK and France to share security information concerning potential threats, mount swifter and stronger initial responses to serious security incidents, coordinate more efficient joint responses and cooperate more effectively in the aftermath of an attack or incident, a spokesperson said.