Hyderabad, Jul 16 (IANS): Telugu Desam Party (TDP) chief N. Chandrababu Naidu and legislators Friday launched a 'bus yatra' to Babli near the Andhra Pradesh border to start a "national debate" on the controversial dam across the Godavari being built by Maharashtra.

The Maharashtra government stepped up security along the border to stop them as four buses carrying Naidu, other TDP legislators and leaders of Lok Satta left for Babli, near the border with Adilabad district of Andhra Pradesh.

Chief Minister K. Rosaiah spoke to Naidu over phone Thursday night, advising him to call off his 'bus yatra' that he said would heighten tensions between the two states.

Naidu, however, ignored Rosaiah's appeal as well as the decision of the Maharashtra government not to allow him to enter the state.

Naidu had invited Rosaiah and leaders of all parties, including the ruling Congress, to join the 'yatra'. But only leaders of the Lok Satta joined him.

The TDP chief and former chief minister told reporters that it was a fact-finding mission aimed to start a national debate on Babli and 13 other illegal projects across Godavari.

He alleged that Maharashtra was going ahead with the works on Babli in violation of Supreme Court orders.

He said the Andhra Pradesh government was doing nothing to stop the projects, which would prove disastrous for the state and turn Telangana into a desert.

Maharashtra has sounded an alert along its border with Andhra Pradesh to stop the 'yatra'. Police have erected barricades and formed check posts to check every vehicle entering the state.

The authorities in Nanded district of Maharashtra have imposed prohibitory orders around the project site as leaders of various parties of the neighbouring state have also reached there to protest the visit by TDP leaders.

In 2007, the Maharashtra Police used force to stop TDP leaders led by legislator N. Janardhan Reddy from heading towards the Babli dam.

The opposition party has alleged that the Congress government was not showing seriousness to stop the illegal projects in Maharashtra which would take away the state's rightful share of Godavari waters.

Rosaiah plans to take an all-party delegation to Delhi later this month to meet Prime Minister Manmohan Singh to urge him to ask Maharashtra to stop construction of illegal projects.