India, Dec. 9 -- On her 79th birthday, Congress veteran Sonia Gandhi briefly responded to reporters with a smiling "Vande Mataram", a remark that immediately fed into a political storm already intensifying for two days over the national song.

The exchange came after a fierce round of attacks and counterattacks between the ruling BJP and the Congress, triggered by Prime Minister Narendra Modi's accusation that former Prime Minister Jawaharlal Nehru had objected to Vande Mataram as it might "irritate Muslims", echoing, he claimed, Muhammad Ali Jinnah's stance.

Although Rahul Gandhi was initially expected to respond, it was Priyanka Gandhi Vadra who took the lead.

She also hit out at the Prime Minister and the BJP for "selectively quoting...