The Federation of Cypriots in the UK urged British defence secretary John Healey on Tuesday to justify a multi-billion-pound contract linked to the sale of Eurofighter Typhoon jets to Turkey.

The federation warned that the agreement, signed last week, may breach UK strategic export licence criteria and Britain’s obligations as a guarantor power under the 1960 Treaty of Guarantee.

The letter expressed concern that supplying advanced combat aircraft to Turkey could “create serious risks to Cyprus’ security,” citing Turkey’s ongoing military presence in the north, repeated violations of Cypriot airspace and waters, and the deployment of F-16s.

It called on the British government to provide assurances that equipment sold to Turkey will not be used to “perpetuate the occupation or strengthen Turkey’s military presence in Cyprus” and asked whether Ankara had committed to not deploying the jets in violation of international law.

The agreement, signed in London by Healey and Turkish Defence Minister Yasar Guler, covers UK-based training for Turkish pilots and ground crew as part of an £8 billion Typhoon deal.

Defence firms including BAE Systems, Leonardo UK, MBDA, Rolls-Royce and Martin-Baker will supply components and training equipment.

The British government described the deal as reinforcing NATO’s combat air capability on its eastern flank and marking the next phase of Turkey’s entry into the Eurofighter programme.