Tunku Abdul Rahman was worried about the impact of Singapore's leftist influence in a unified Malaysia. He demanded that Singapore's political opposition be arrested as a condition of merger. The PAP was hesitant about the arrests as they could damage the PAP's popularity in Singapore. However, the Brunei Revolt of 8 December 1962 gave the PAP a 'heaven sent opportunity' to justify the arrests. The Barisan's open support of the Brunei revolt gave the PAP an excuse that the arrests were to prevent possible communist subversion and safeguard the security and safety in Singapore.