Over 230 former ministers, ambassadors and diplomats urge the Indian government to impose stricter sanctions on Israel, including a full arms embargo and suspension of trade ties.
The group argues current measures are insufficient and calls for each for blocking products from illegal settlements and investigating possible war crimes involvement by nationals on both sides.
Saying Delhi should not wait for EU decisions, they cite Luxembourg's refusal to approve Israeli bonds as proof that a large country is not needed to take effective action.
Similar appeals were made last September and August by envoys from France and Britain, but the government has yet to respond with concrete steps.
Despite demands for a 180-degree policy shift, the ex-officials stress that keeping the issue on the agenda is mandatory given the severity of the situation in Gaza and West Bank.