However, the merger of the British crown colony of Penang into the vast Malay heartland alarmed some quarters of Penang's population. Questions were raised over economic and ethnic issues, such as the citizenship of non-Malays, greater trade regulations imposed on Penang by the central government in Kuala Lumpur and the introduction of export duties for trade with the rest of Malaya. Consequently, the Penang Secession Committee, formed in 1948, proposed to exclude Penang from the Federation of Malaya, which would allow Penang to either retain its links with the British Empire or form a political union with Singapore. The movement was led by D.A. Mackay, then the chairman of the Penang Chamber of Commerce, and included the Penang Muslim Chamber of Commerce, the Penang Chinese Chamber of Commerce, the Penang Straits Chinese Association, the Penang Eurasian Association and the Penang Indian Chamber of Commerce.