The French drove the advanced posts of the garrison in on 19 December and surveyed the town to decide on their point of attack. Seeing the apparent advantage of the high ground to the east, they opened trenches on 22 December and by dawn on 29 December were ready to fire their
sixteen-pounder cannon. It only took a few hours for the walls to tumble down and to make a large breach. The small walled town of Tarifa seemed almost impossible to defend. Overlooked at short range by higher ground, with walls unprotected against artillery fire, it would easily fall to a serious attack. Skerrett proposed abandoning the defence and embarking on ships. Captain
C. F. Smith of the
Corps of Royal Engineers strongly opposed the idea; he had noted that inside the walls, the ground level was much lower which combined with a deep narrow river that flowed through the town would make that assault quite hazardous. Skerrett was checkmated when the ships were ordered back to Gibraltar, the commanders being forbidden to embark a single soldier, by General Campbell, the Governor of Gibraltar. Smith having foreseen where the French would attack had prepared internal defences against the impending assault. The 14-foot sheer drop inside the wall would trap the French from retreating and every house overlooking the area was loopholed and garrisoned, with retrenchments formed to trap the enemy. All debris was cleared from inside the wall, despite the grape being fired by the besiegers. Surrender terms were offered and refused. The night of 29/30 December had very heavy rain, with the portcullis defending the river entrance bent inwards by the flood of water and the defences requiring quick repairs before the French attacked at dawn. French Grenadiers advanced along the now dry river bed trying to enter through the portcullis, however it held and the 87th Regiment blunted their attack with withering fire. Moving to their left they tried for the breach, and meeting more fire, retreating back to the river bed, which was covered by a cannon mounted on a tower, firing grape, they huddled amongst their dead and wounded until they eventually retreated back to their camp. This was the only attack that was made, the weather became extremely inclement for several days, the torrential rain damaging the French batteries and trenches so that on the night of 4 January 1812, they were heard pulling back. Going over to the offensive, the Allies sallied forth in the morning, forcing the French to retreat, leaving their siege equipment behind. ==Aftermath==