A day before the launch of the much-touted 3,570-km 'Bharat Jodo Yatra', the Congress on Tuesday said it is a "transformational moment" for Indian politics and a "decisive moment" for the party's rejuvenation.

With the launch of the Yatra on Wednesday at a mega rally here, the Congress is seeking to flag economic disparities, social polarisation and political centralisation, while attempting to make gains in what it often described as battle of ideologies.

Before the launch, former Congress president Rahul Gandhi will take part in a prayer meeting at Rajiv Gandhi memorial in Sriperumbudur on Wednesday. He will then attend an event in Kanyakumari where Tamil Nadu Chief Minister M K Stalin, Rajasthan's Ashok Gehlot and Chhattisgarh's Bhupesh Baghel will be present.

Stalin will present a national flag made of khadi to Gandhi who will hand it over to Seva Dal workers who will manage the Yatra throughout.

After the event at the Mahatma Gandhi Mandapam where Stalin will be present, Rahul Gandhi and other Congress leaders will walk to the seaside venue of the rally where the yatra will be formally launched.

Sources said a message from the Congress president could be read or a video message from her be shown at the event. Sonia Gandhi's mother passed away recently in Italy. Both she and party general secretary Priyanka Gandhi Vadra are abroad.

Rahul Gandhi arrived in Chennai Tuesday night.

Congress general secretary in-charge communications Jairam Ramesh said the Yatra is a "transformational moment for Indian politics and it is a decisive moment for the rejuvenation of the party".

A final check on the preparations at the venue near the 'Mahatma Gandhi Mandapam' was done by general secretaries K C Venugopal and Ramesh along with senior leader and Yatra organisation panel in-charge Digvijaya Singh.

"There is a lot of enthusiasm and excitement among the Congress workers across India," Ramesh told PTI.

"Even in states where the Yatra is not passing through, people are excited. In each state the Congress will organise similar Yatras on a smaller scale, may be of 50 km or 100 km on the main theme of uniting India, an India being torn apart by economic inequalities, social polarisation and over-centralisation," he said.

In an apparent dig at the government, Ramesh said it will not be a yatra of speeches where announcements are made. Rahul Gandhi, accompanied by 118 leaders, will interact with various groups, he said.

"The party is focused on making Bharat Jodo Yatra successful because it is the largest mass mobilisation programme it has undertaken in Independent India."

"It is the longest yatra undertaken by the party. It's a turning point for India's political history. Padyatras have a significance of their own and this is transformational politics. This is what politics is about, not of abuse, vendetta and vilification," he said.

Tagging a report on a meeting of top BJP leaders in Delhi Tuesday, Ramesh tweeted, "The launch of the Congress' Bharat Jodo Yatra tomorrow from Kanyakumari has clearly sent a powerful message to the ruling establishment. When they can't meet deadlines, they resort to managing headlines!"

In a video message, Priyanka Gandhi Vadra urged people to join the Yatra wherever possible. She asserted the Yatra was needed as "negative politics was being practised in the country and real issues were not being discussed". It aims to put focus on people's issues such as price rise and unemployment, she said.

Though the march, covering 12 states and two Union Territories in about five months, will be formally launched at the rally, it will actually begin at 7 am on Thursday when Gandhi and other Congress leaders will embark on the march.

Before the launch, Rahul Gandhi will visit Vivekananda Rock Memorial, Thiruvalluvar statue and Kamaraj Memorial in Kanyakumari.

He has said with all paths blocked, the Congress now has to go to the people and tell them the truth which is why the party is undertaking the Yatra.

"The government has blocked all paths for us... Congress leaders, opposition and people cannot make speeches in Parliament. Our mic is put off. We want to talk about China's attack but can't. We want to talk about unemployment and inflation but can't," Gandhi said at the 'Mehngai Par Halla Bol Rally' on Sunday.

"There is attack on our institutions, whether it is media, Election Commission or judiciary. There is pressure. All roads are closed for us. Only one way left, to go to the people. The country's truth has to be told to the people, that's why the party is undertaking the Yatra," he said.

The march will move in two batches from 7 am to 10:30 am and from 3:30 pm to 6:30 pm. While the morning session will include fewer participants, the evening session will see mass mobilisation. The participants plan to walk around 22 to 23 km daily.

The Congress has asserted its Yatra is not a 'Mann Ki Baat', but to ensure people's concerns reach Delhi.

It has classified 119 leaders, including Rahul Gandhi, as 'Bharat Yatris' who will walk the entire route. About 30 per cent of 'Bharat Yatris' are women. The average age of Bharat Yatris is 38. About 50,000 citizens have also registered to participate in the Yatra.

To coincide with the launch of the Yatra on Wednesday, 'Prarthana Sabhas' will be held by the Congress' state units at 5 pm, a leader said. At 7 am Thursday, 10 km foot marches will be held at block level.

After reaching Kerala on September 11, the Yatra will traverse through the state for the next 18 days, reaching Karnataka on September 30. It will be in Karnataka for 21 days before moving north.

It will pass through Thiruvananthapuram, Kochi, Nilambur, Mysuru, Bellary, Raichur, Vikarabad, Nanded, Jalgaon, Indore, Kota, Dausa, Alwar, Bulandshahr, Delhi, Ambala, Pathankot, Jammu, and end in Srinagar.