Baptized Operation "Vulcan", its plan fixed the major offensive on May 6, after two preliminary operations:
• On May 4, the 19th French corps would attack the first to try to blow up the hinge of the Zaghouan, at the junction of the two enemy armies, an action which had the effect of attracting the opposing reserves to that side and encouraging surprise at Medjez-el-Bab;
• On May 5, the British 5th Corps will take Djebel-bou-Aoukaz, between Medjez and Tébourba, on the south bank of the river, so as to free the left flank of the main attack from any threat. Then, when the latter had made the breakthrough, it would cover the Armored Division Games to the north which would push on Tunis; dawn east of Medjez, on a very narrow front, with two infantry divisions in the front line (4th British 4th Indian), supported by concentrated artillery fire, then, at daybreak, by a bombardment unprecedented air.
The two divisions will be followed by 6th and 7th Armored Divisions, which will follow in their footsteps from the start "so that there is no delay or hesitation in overtaking the infantry immediately that a breach will have been opened by them".
The two armored divisions will rush straight ahead on Massicault, Saint-Cyprien and Tunis "without worrying about what might happen on their flanks".
They will thus burst into the immediate defense belt of the capital, before the enemy has e u time to occupy it or reinforce it. Their first objective will be Saint-Cyprien. The two infantry divisions will follow them as quickly as possible while clearing them.
Such was the "Vulcan" plan, based on the power of the shock and the lightning speed of the exploitation. It was also so on another essential factor:surprise.
To achieve surprise on the decisive axis of effo, the Germans had to be kept under the illusion that the main attack would occur further south. A veritable stratagem was therefore mounted, with the intention of retaining as many tanks and anti-tank guns as possible far from the sector chosen for the rupture.
While doing nothing to camouflage the 1st D.B. in the sector from the Sebkret, General Anderson organized a large concentration of tanks, real or dummy, and large movements of trucks in the region of BouArada, while he carried, by night and with the greatest precautions, the 6th and 7th Armored Divisions in the Medjez bridgehead.