He said RSS had been recently active in ensuring that Gujarat Chief Minister Narendra Modi was named as BJP's Prime Ministerial nominee.
"If this is not politics, then I do not know what is," he said.
The Congress leader said it was well-known that speeches made by RSS chiefs on Vijaya Dashami over the years are full of reference to politics and even Pakistan.
"RSS is fond of claiming that it was a cultural organisation but it has never done anything even remotely related to culture," Singh said on Saturday.