By the second half of 1965, the stormy political climate in Malaysia showed no signs of easing. Tunku Abdul Rahman, who had become the Malaysian Prime Minister, was pressed to intervene to avoid a repeat of the communal clashes that had taken place in 1964. During his London trip to attend the Commonwealth Prime Ministers' Conference in June 1965, the Tunku decided that severing Singapore from the federation was the only course and communicated this to his deputy, Tun Abdul Razak, who was instructed to sound out the senior Malaysian ministers and lay the groundwork for separation.[14] By the time the Tunku returned to Kuala Lumpur on 5 August, Singapores days in the federation were numbered.[15]
The week leading to 9 August 1965 was a busy time for the leaders of both countries as by this time, separation had become a certainty.[16] Negotiations were, however, done in complete secrecy. In Singapore, not only were civil servants and permanent secretaries kept in the dark, but some senior *** cabinet members, most notably Deputy Prime Minister Toh Chin Chye and Culture Minister Rajaratnam, were also clueless. Leading the negotiations for Singapore was then Finance Minister Goh Keng Swee, and for Malaysia, Tun Razak.[17] Razak was aiming to convene a federal parliament sitting on 9 August and was pushing for the legal paperwork for the release of Singapore to be tabled at that session.[18] In Singapore, Lee had asked then Law Minister E. W. Barker to draft the separation agreement at the end of July, along with other legal documents such as the Proclamation of Independence.[19]
As the deadline of 9 August neared, Goh and Barker made arrangements to travel to Kuala Lumpur to finalise the separation, arriving quietly in the capital on 6 August. Lee, who was in Cameron Highlands at that time, left for Kuala Lumpur and also arrived on 6 August to study and approve the separation documents. Thereafter, the separation draft prepared by Barker occupied the attention of five men Razak, Malaysian Attorney-General Kadir Yusof, Malaysian Home Affairs Minister Ismail bin Dato Abdul Rahman, Barker and Goh. The final version, which included a few amendments and insertions, were typed late that night and signed by Goh, Barker, Razak, Ismail, Malaysian Finance Minister Tan Siew Sin and Malaysian Minister for Works V. T. Sambanthan well after midnight.[20]
After Lee was shown the final signed separation documents by Barker, he called Toh and Rajaratnam in Singapore to meet him the following morning. Arriving in Kuala Lumpur separately on 7 August, both Toh and Rajaratnam were particularly distraught when Lee told them of the news, and were not willing to sign the agreement.[21] However, a letter written by the Tunku to Toh stressing the formers irrevocable decision that there was absolutely no other way out left them with no choice.[22] Realising that their persistence to pursue the status quo could well mean bloodshed, both Toh and Rajaratnam reluctantly signed.[23]
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Many rallied behind the news of the separation with relief although the manner of its announcement came as a shock and was initially greeted with disappointment and regret.[32] It was slightly less than two years ago that the people of Singapore had backed Lees merger through their votes in the September 1962 referendum.[33] However when merger came, the greater share of it was marked by constant differences and bitter political wrangling between leaders of the two nations.[34] Although all signs were pointing to trouble, very few were prepared for the dramatic end to Singapores union with Malaysia.
http://eresources.nlb.gov.sg/history/events/dc1efe7a-8159-40b2-9244-cdb078755013