Taking the oath of office as Prime Minister on 19 October 1963 at City Hall in the presence of Yusof bin Ishak, then the Yang di-Pertuan Negara of Singapore.
### Singapore as a Malaysian state ###
The public had shown its trust in Mr Lee and his team by voting overwhelmingly in favour of the PAP’s merger proposal in the September 1962 referendum.
On 16 September 1963, Singapore, together with Sabah and Sarawak, became part of the Federation of Malaysia. Just five days later, the PAP was re-elected as the government after winning 37 out of the 51 seats in the 1963 Singapore general elections. The PAP won Malay constituencies too, though the Tunku had personally campaigned on behalf of UMNO candidates in Singapore.