The British had been forewarned by Ultra decrypts of German wireless communications and rushed reinforcements from Tripoli and Benghazi before the Axis attack, which was a costly failure.

General Erwin Rommel, the commander of Army Group Africa (Heeresgruppe Afrika), could not afford to lose forces needed for the defence of the Mareth Line and the effort was abandoned at dusk that day.

During the day the Luftwaffe and Regia Aeronautica had made a maximum effort with little effect against the Allied anti-aircraft defence and the Desert Air Force (DAF).

The Panzerarmee evaded British outflanking moves but traffic jams, fuel shortage, poor weather and air attacks reduced the retreat to 6–7 mi (9.7–11.3 km) per day.

[1] Rommel had wanted retreat to Wadi Akarit in the Gabès area, 120 mi (190 km) further west, where the non-motorised troops could defend the narrow gap between the Mediterranean and the Chott Djerid.

On the night of 11/12 December, the British attacked and on the following evening the Panzerarmee resumed its retreat and despite the chronic fuel shortage, evaded another outflanking move.

The Panzerarmee took up a defensive position at Buerat on 29 December but this was poorly fortified, wide open to an outflanking manoeuvre and vulnerable to being cut off by an attack on Gabès by the First Army from southern Tunisia.

Comando Supremo intended the line to be held indefinitely but Rommel considered it too vulnerable to another flanking move, unlike the Wadi Akarit position, another 40 mi (64 km) back.

The 5th Panzer Army had been formed on 8 December and winter weather began in mid-month, which was further to the advantage of the Axis defenders, as Panzerarmee Afrika continued its retreat from El Alamein, towards southern Tunisia.

[5] Southern Tunisia is a region of broken terrain, with rocky ridge lines and desert, which obstruct manoeuvre; opposite a bight where the north–south coast opens to the east, a semi-arid, scrub covered coastal plain is met inland by the Matmata Hills which run south to north.

In 1938, the French judged Jebel Dahar to be impassable to motorised transport and had not extended the Mareth Line any further inland but 1943 motor vehicles had much better performance.

[10] The attack was set for 6 March to give time for the units involved in Unternehmen Morgenluft (the Battle of Sidi Bou Zid) to replace casualties and re-organise.

The 15th Panzer Division was to move from Djebel er Remtsia towards Hir en Nraa followed by its infantry and the Reconnaissance units were to cut the Foum Tatahouine–Medenine road to prevent the movement of British reinforcements.

[b] On 5 March, the Luftwaffe and Regia Aeronautica were to bomb Allied airfields and cover the assembly of the ground force and on 6 March were to attack British artillery positions east of Zemlet el Lebene, close the forward Allied airfields, provide fighter escorts for the ground attack and reconnoitre from Tatahouine to Ben Gardane.

[10] Long before the Eighth Army reached the port of Tripoli, thought had been given to an attack on the Mareth Line and the LRDG had been sent to survey the land south of the Matmata Hills.

The next day the Free French Flying Column and the 1st Infantry Battalion Marine and Pacific arrived with General Philippe Leclerc, after a march across the Sand Sea from Lake Chad, to join the Eighth Army.

On 26 February, the Eighth Army had only about one division at Medenine, most of its tanks were with X Corps (Lieutenant-General Brian Horrocks) at Benghazi, 1,000 mi (1,609 km) away and an attack on the Mareth Line could not be ready before 20 March.

At 5:36 a.m. on 6 March, Allied code breakers sent notice to Montgomery of the thrust line of the attack and that it was to begin at 6:00 a.m.[14] It was foggy when the Axis bombardment of the British forward positions began at 6:00 a.m., and for ninety minutes tanks, guns and other vehicles emerged from the heights between Toujane and Kreddache.

As dusk fell, the attackers withdrew, a detachment of the King's Royal Rifle Corps and other units at Haddada having remained undisturbed, despite being isolated when the FFF Column on the right was forced back, during an Axis outflanking move.

[23] There were rearguard actions from 7–8 March, as the Germans withdrew to the Mareth Line and Gabès but British attempts at pursuit were frustrated by the weather and the speed of the Axis withdrawal.

On 10 March, some heights were still occupied and there was sporadic long-range artillery fire; Rommel left Africa the same day for the last time, leaving Arnim in command.