Later, he took a break from the Congress party and began to work in the SNDP Yogam. During his long association with the SNDP Yogam of over 13 years, he served as its General Secretary for over a span of 10 years and President and Chief of the SN Trust. Under his leadership the SNDP Yogam gave emphasis to the field of education and started many educational institutions. SNDP Yogam celebrated its Golden Jubilee year while Sankar was the General Secretary in 1953. As part of a year-long celebration he organised an Exhibition in Kollam which is marked in the history of the State as 'SNDP Kanaka Jubilee'