A day after Rajasthan Chief Minister Ashok Gehlot announced his candidature for the Congress president's post, nomination forms for party leader Shashi Tharoor were on Saturday collected from the party headquarters here with sources saying he is likely to file his papers on September 30.

Tharoor's close aide Aalim Javeri took the forms on his behalf from the office of the party's central election authority chairman Madhusudan Mistry on the first day of the start of the nomination process, all but confirming an electoral face-off for the top party post with Gehlot.

The nomination form is likely to be filed by Tharoor on the last day of the nomination process on September 30 as the idea is to collect nomination-endorsing signatures from across the country, sources told PTI.

At least 10 Pradesh Congress Committee delegates are needed to endorse a candidate.

After over two decades, the Congress is set to see a contest for the post of party chief with Gehlot, who has announced his candidature, expected to take on Tharoor.

Tharoor on Monday had met Sonia Gandhi and expressed his intention to contest the poll. The Congress president conveyed she would stay "neutral" in the elections, according to sources.

Sonia Gandhi had welcomed the idea of more people contesting the poll and dispelled the notion that there would be an "official candidate".

Rajasthan Chief Minister Gehlot became the first person to announce his candidature for the AICC presidential poll on Friday and said Rahul Gandhi has told him that no one from the Gandhi family should become the next party chief.

According to a notification issued by the party on Thursday, the process for filing nominations for the election will be held from September 24 to 30.

The date for scrutiny of the nomination papers is October 1, while the last date for withdrawal of nominations is October 8.

The final list of candidates will be published at 5 pm on October 8.

The polling, if needed, will be held on October 17. The counting of votes will be taken up on October 19 and the results will be declared the same day.

More than 9,000 Pradesh Congress Committee (PCC) delegates will vote in the poll.

The Congress last saw a contest for the party president's post in November 2000. Jitendra Prasada had lost to Sonia Gandhi in 2000 and before that, Sitaram Kesri had defeated Sharad Pawar and Rajesh Pilot in 1997.

Meanwhile, senior Congress leader Abhishek Manu Singhvi urged party leaders to refrain from commenting on their colleagues applying for the post of AICC president and said "fair-minded democratic free speech values" that the party has championed must be maintained.

Earlier, Congress General Secretary in-charge of Communications Jairam Ramesh had asked the party spokespersons and the Communications department office-bearers to refrain from commenting on any colleague contesting the elections.

This comes after party leader Gourav Vallabh taunted Tharoor over his probable bid for the post of All India Congress Committee (AICC) president.

Vallabh had also voiced support for Gehlot, who many believe has the backing of the current leadership.