The implementation of the Federation of Malaya constitution based on the Revised Constitutional Proposals on 1 February 1948 and the decision of the MCP to launch an armed rebellion marked the beginning of the end for the PUTERA-AMCJA coalition and AMCJA as a whole. With the declaration of the nationwide emergency, the constituent organisations either withdrew from the coalition, went underground, or in the case of the MDU, voluntarily dissolved itself and the AMCJA ceased to exist as a body.