Britain is sending its most sophisticated mobile air defense kit to Poland to secure NATO’s eastern flank, The Sun has revealed.

The army’s new Sky Saber radar and missile system is capable of hitting an object the size of a tennis ball moving at the speed of sound.

Mobile units can be deployed to form a 240 km long “no-crossing air line”, which extends almost the entire length of the Polish-Ukrainian border.

Up to two dozen missiles can be controlled simultaneously to intercept a swarm of targets such as drones, rockets or aircraft.

The Sky Saber entered service only late last year and has been used to defend the Falkland Islands from Argentine air raids until now.

The truck-based system consists of giraffe radar units and a Landsepter missile launch platform – with a central control unit for eastern Poland.

Each component is mounted on the back of the trucks so that they can be deployed quickly.

The units are expected to leave the UK shortly.

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The Sun understands that they will be accompanied by vital support and logistical support.

Last night the Defense Ministry said the deployment was temporary as part of NATO exercises.

A spokesman said: “As part of our commitment to European security, the UK will support the long-planned NATO exercise Ramstein Legacy 2022 with the deployment of the Sky Saber defensive system in Poland.”