Amid intense lobbying for the chief minister's post in Karnataka, the three central observers deputed by the Congress on Monday returned to the national capital after speaking individually to the newly elected MLAs.

The observers will hand over the report on the views expressed by the majority of the MLAs to party president Mallikarjun Kharge later in the day.

Former chief minister Siddaramaiah and PCC president D K Shivakumar are both staking claim to the top post and are lobbying hard for it.

Kharge had appointed former Maharashtra chief minister Sushilkumar Shinde, party general secretary Jitendra Singh and former AICC general secretary Deepak Babaria as observers for the election of the CLP Leader of Karnataka.

The three leaders along with AICC general secretary in-charge of Karnataka Randeep Surjewala left Bengaluru for Delhi and will meet Kharge.

The observers spoke individually to all the newly elected MLAs and sought their opinion on who should be the chief minister of the state.

They spoke to all the MLAs after dinner at a private hotel on Sunday night and completed the process.

A poster war by supporters of both leaders had also erupted soon after the party won the election.

Earlier, during the meeting of the Congress Legislature Party in Bengaluru on Sunday evening the MLAs passed a one-line resolution authorising the party president to appoint the CLP leader in the state who would be the next chief minister.

The Congress staged a stupendous victory in the May 10 assembly election by winning 135 seats out of a total of 224.