Mukhtar Ahmad Bhat, vice-president the Yuva Janata Dal (United), was on Thursday morning shot dead by militants at Chattabal in the summer capital Srinagar.
Police said Bhat, a surrendered militant, died on the spot.
The killing is believed to be related to the Lok Sabha elections due in April-May 2004. Security to prominent political activists of all major parties in Jammu and Kashmir had been strengthened following militant threats.