The “Westforce” trapped

As the battle unfolded, Percival conferred with General Heath and General Bennett, commanding the 8th Australian Division, which held ground east of Johore. Bennett was ordered to make an orderly withdrawal and reach Serandah on January 16, Port Dickson on January 21, and Tampin on January 24. Percival believed that if he could hold the enemy on land until By mid-February he could replace Bennett's division with the 18th Division, which by then would have arrived, and Bennett would be in a position to launch a counter-offensive. On January 8, Wavell, who had just arrived in Singapore by air, attended a conference at Segamat, where the relief of the 3rd corps by the Australians and the defense of Johore were discussed.
But all decisions soon proved useless as the speed, momentum and weight of the Japanese attack intensified. While Wavell was still in conference, the 5th Imperial Guards Regiment reached Ipoh; Yamashita arranged for the rest of Mutaguchi's 18th Division to be landed at Endau, thus threatening the British line of retreat from northern Johore. Meanwhile, the Japanese 5th Division was advancing and, on the 11th, at 8 p.m., entered Kuala Lumpur, the main base of the 3rd Corps. Gasoline and fuel oil reserves had been burned, but the Japanese seized a huge amount of food and equipment. It was on this day that Yamashita decided to rest the 5th Division, which had been fighting non-stop for five weeks, and to send the Imperial Guards Division to Malacca on the west coast, south of Port Dickson. He also decided that the 18th Division would land at Songkhla, not Endau, and descend on Johore by road.
Percival's only hope, as to the defense of Johore, Yamashita thought, was Muar line; so he ordered Nishimura to force the passage, thus threatening British communications by the main road. Nishimura's opponent in this area was General Bennett, who now commanded a motley unit called "Westforce", consisting of the Australian 8th Division (minus the 22nd Brigade), the 9th Indian Division and a number of units brought from Singapore. Bennett's plan was to fix the Japanese on the MuarBatu Anam line and for this purpose he placed the Australian 27th Brigade at Gemas.
Bennett felt that in order to hold the Japanese in check he had to set them a series of ambushes on their axis of progression; at first he achieved encouraging success. But the strength of the Japanese continued to grow and, on the 11th, General Matsui took over the command of operations. No advance was recorded but the Imperial Guards Division began to descend along the coast and soon Bennett saw his communications threatened. Worse still, an Indian unit, launched in a counter-attack on Muar, was itself ambushed. General Nishimura crossed the Muar without difficulty and the "West-force" had only to beat a retreat.
On January 19, Wavell learned that no plan had been drawn up detailed neither for the retreat to the island of Singapore nor for its defence. He sent a message to Churchill to warn him that in his opinion the base would no longer be defensible once Johore was lost. At the same time, he cabled Percival:“You have to solve the problem of the withdrawal of troops from the mainland . . . and find a solution to prolong the defense on the island. The next day Percival made known his plan, which called for the retreat of his forces in three columns and the establishment of a bridgehead that would cover the pass through Johore Bharu. On the 20th, Wavell returned to Singapore by air and found that, despite his instructions, very little had been done to strengthen the defenses to the north of the island. He urged Percival not to waste another minute. A message from the Chiefs of Staff supported his instructions. These demanded that the guns of the fortress be transformed to respond to a land attack; that barrages be prepared on the landing points in the Straits of Johore and that self-contained defensive formations be created, using all available weapons.