For the past six weeks Indians have been mesmerised by the stunning success of the Aam Aadmi party, which has propelled its 45-year-old activist leader, Arvind Kejriwal, to chief minister of Delhi. The AAP – or Common Man party – is only a year old but its popularity is challenging the supremacy of India’s two main political parties, the left-leaning Congress and the Hindu nationalist Bharatiya Janata party.

Yet despite its many commendable features, the AAP is not the party needed to revive investment and growth and unlock India’s potential. Mr Kejriwal’s gentle, charming rhetoric seems to hide illiberal instincts. His party, furthermore, could prevent the formation of a stable government in this year’s national elections if it diverts enough votes from Narendra Modi of the Bharatiya Janata party, the leading contender.

The AAP has rapidly given many Indians a wonderful sense of nationhood. Its transparent fundraising contrasts with the murky electoral financing of other parties. Its strident rhetoric has forced parliament to enact anti-corruption legislation that had been languishing for years. Its politicians’ frugality has embarrassed those of other parties who live in sprawling bungalows with gun-toting security brigades.