The merger of seven 'mandals' of Khammam district with Andhra Pradesh rocked Telangana assembly on Monday with ruling and opposition parties blaming each other.

While Congress party tried to corner the Telangana Rashtra Samithi (TRS) government for failing to stop the merger, the ruling party hit back at the main opposition, saying the decision was taken by the previous United Progressive Alliance (UPA) headed by it.

Irrigation minister T. Harish Rao blamed then union minister Jairam Ramesh for th merger of seven 'mandals' and said the decision was implemented by BJP-led NDA government.

He also criticised the Congress for not opposing the relevant bill when it came up in Rajya Sabha. Amid heated exchange over the issue, the Congress party staged a walk-out from the House.

The issue came up during question hour when Congress member Ajay Kumar wanted to know the steps being taken to get due share of electricity for Telangana from the Lower Sileru hydro-electric project. He said the state had lost not just 'seven' mandals but also the project to Andhra Pradesh.

Kumar also wanted to know why Chief Minister K. Chandrasekhar Rao failed to take an all-party delegation to Delhi to mount pressure on the central government despite a resolution passed in the assembly.

When Harish Rao turned the tables on the Congress, the main opposition took exception to naming Jairam Ramesh.

Chinna Reddy of the Congress blamed union minister M. Venkaiah Naidu for the merger of Telangana villages with Andhra, evoking protest from the BJP.

It was in July 2014 that the parliament passed a bill to transfer seven 'mandals' comprising 136 villages and 211 hamlets to the East Godavari district of Andhra Pradesh to facilitate construction of Polavaram project across the Godavari river.

The NDA government went ahead with the merger despite strong protest from Telangana.