Australia is on the brink of its biggest ever defence deal as the British government is set to buy an Aussie-built radar, considered the best in the world.

This masthead can reveal the contract to sell a Canberra-built radar system to the UK would be worth more than $10 billion.

This masthead can reveal the contract to sell a Canberra-built radar system to the UK would be worth more than $10 billion.