Reflecting the possible line-up against BJP, NCP chief Sharad Pawar, Trinamool Congress' Sudip Bandyopadhyay and DMK's Kanimozhi were among leaders of 19 parties who attended a dinner hosted by UPA Chairperson Sonia Gandhi at her residence on Tuesday.

Considerable significance is being attached to the dinner in the midst of speculation about the political realignment that could take place ahead of next year's Lok Sabha elections.

The meeting also took place against the backdrop of stand off with the government in parliament that has seen continuous disruptions since the start of second half of budget session on March 5.

Congress President Rahul Gandhi later said there was "much political talk" during the dinner meeting.

He also said the leaders reflected tremendous positive energy, warmth and genuine affection.

"Fabulous dinner tonight, hosted by UPA Chairperson, Sonia Gandhi Ji. An opportunity for leaders from different political parties to meet and bond, informally.

"Much political talk but much more important - tremendous positive energy, warmth and genuine affection," Gandhi said in a tweet.

Some leaders later said that the dinner was part of effort to forge a front against the BJP in the Lok Sabha battle next year and regional rivals were coming together.

"The effort is on. The effort is going on. This is a part of that effort," said expelled Janata Dal-United leader Sharad Yadav said when asked if there will be a front of opposition parties in 2019.

Rashtriya Janata Dal leader Tejashwi Yadav said the the effort is on to get the opposition united.

"You can also see NDA allies are also angry. Chandrababu Naidu is angry, Akalis are also angry. They are losing faith in NDA's leadership. TRS is not happy."

"Laluji's (RJD supremo Lalu Prasad) effort to have a mahagathbandhan (grand alliance) at the national level, this was a positive move towards that," he said and accused the BJP-led government of political vendetta against its opponents.

Congress Communications incharge Randeep Singh Surjewala told reporters that the leaders discussed ways to fix accountability of the Narendra Modi government in parliament.

He accused the government of running away from debate in parliament on the Rs 12,600 crore PNB fraud case as also failing to tackle unemployment and problems of farmers.

"When the government does not have interest to run Parliament, then it is natural that leaders of opposition parties, who are concerned about the problems faced by the people, will discuss the country's politics. There will be unofficial discussion on how to fix accountability of the government," he said.

Leaders who attended the dinner also included National Conference leader Omar Abdullah, Samajwadi Party's Ram Gopal Yadav, Bahujan Samaj Party's Satish Chandra Misra, All India United Democratic Front's Badrauddin Ajmal, Rashtriya Janata Dal's Misa Bharti and Tejashwi Yadav, Jharkhand Mukti Morcha's Hemant Soren, Communist Party of India-Marxist's Mohammad Salim, and Communist Party of India's D. Raja.

IUML's P. K. Kunhalikutty, Kerala Congress-Mani' Jose K. Mani, Jharkhand Vikas Morcha-Prajatantrik's Babulal Marandi, Revolutionary Socialist Party's N. K. Premachandran, veteran socialist leader Sharad Yadav, Rashtriya Lok Dal's Ajit Singh and Janata Dal-Secular's Kupendra Reddy were also present as was Hindustan Awam Morcha leader Jiten Ram Manjhi, who had quit the NDA last month.

Besides Rahul Gandhi, former Prime Minister Manmohan Singh, Leader of Opposition in Rajya Sabha Ghulam Nabi Azad, Leader of Congress in Lok Sabha Mallikarjun Kharge and party leaders Ahmed Patel, and A.K. Antony were among those present.

Seventeen opposition parties had come together against the BJP-led NDA during the presidential and vice-presidential elections last year and Sonia Gandhi has been holding occasional meetings to nurture the bonding. Party leaders said the group was expanding with Manjhi and Marandi coming to attend the dinner.

It is also noteworthy that Sonia Gandhi took the lead for the get together of the leaders even after Rahul Gandhi has taken over as the Congress President in December last year with the feeling in the Opposition that senior leaders would show deference to her more than to her son.

This dinner is also significant in the context of moves by regional parties like the Telanagana Rashtra Samiti and the Telugu Desam Party which have attacked BJP in the recent past and are said to be jockeying for a third front of parties against the BJP and Congress.