'MD6' was a British naval diversionary undertaking by elements of Admiral Sir Andrew Cunningham’s Mediterranean Fleet to ease the passage of the 'Halberd' convoy supervised by Vice Admiral Sir James Somerville’s Gibraltar-based Force 'H' (26 September 1941).

The ships involved were the battleships Barham, Queen Elizabeth and Valiant, the light cruisers Ajax, Neptune and Australian Hobart, and the destroyers Decoy, Havock, Hero, Hotspur, Imperial, Jervis, Jupiter, Kingston, Kipling and Australian Vendetta.

As part of the undertaking, the light cruiser Ajax and three destroyers were detached from Cunningham’s main force to undertake a nocturnal gunfire bombardment of Tripoli.