Indian Prime Minister Narendra Modi’s ruling Hindu nationalist party on Monday wrested control of the state of West Bengal, an opposition stronghold, in a key election.

The Election Commission of India released partial results showing the Bharatiya Janata Party won at least 124 seats in the 294-member West Bengal assembly, and was leading in 83 others. Final results are expected on Monday evening.

It would be a significant breakthrough for Modi’s party, which had tried for years to dislodge the All India Trinamool Congress government led by Chief Minister Mamata Banerjee. The BJP has never governed West Bengal, a politically influential state, where Banerjee – one of Modi’s most prominent critics – has held power since 2011.

Opposition parties have sharply criticised the polls in West Bengal after the Election Commission removed millions of voters from electoral rolls.

Three other states also took part in the latest election.

The South Asian country of more than 1.4 billion people has 28 states and eight federal territories. Staggered state elections are held at different times across India, with a few state polls scheduled almost every year.