Talks to end the 43-year-old political deadlock on Cyprus broke down acrimoniously yesterday, as Turkish and Greek cypriot negotiators failed to reach compromises over the security of the island.

The collapse of UN-brokered negotiations in the Swiss resort of Crans-Montana brought to an abrupt conclusion attempts to end one of the world’s longest frozen conflicts and heal Europe’s largest diplomatic sore.

“I’m very sorry to tell you that despite the very strong commitment and engagement of all the delegations and different parties ... the conference on Cyprus was closed without an agreement being reached,” announced a clearly crestfallen António Guterres, the UN secretary general.

The failure of the talks came despite high-level backing from both the UN chief and Boris Johnson, the Foreign Secretary, as well as the Greek and Turkish governments.