A woman speaks through a megaphone plastered with a Thai Rak Thai Party logo at a protest rally outside The Nation office yesterday.

In a new round of attempts to oust defiant caretaker Prime Minister Thaksin Shinawatra, two leaders of the People's Alliance for Democracy (PAD) called for the first time yesterday for a "royally-sponsored prime minister".

However, all five core leaders of the PAD met over the matter last night and decided to give Thaksin a final 48-hour ultimatum to step down - before taking a formal stance on such a demand.

"We have finally decided to give Prime Minister Thaksin 48 hours and within that 48 hours if Premier Thaksin has not stepped down to allow political reform to take place, we will come up with a measure that will be made known to the public," Sondhi Limthongkul told the anti-Thaksin demonstration last night.

During an early-morning rally of more than 10,000 protesters on Silom Road, Sondhi and Chamlong Srimuang, on a six-wheeled truck, urged passers-by, residents and office workers to join the PAD rally on Saturday (March 25).

They said the rally, to be held at the Makkhawan Bridge on Rajdamnoen Avenue, would be the people's "unanimous decision" to ask His Majesty the King to solve the political crisis by replacing Thaksin with his "own prime minister".

The rally organisers also asked the crowd to sign a petition supporting the idea of a royally-sponsored premier.

Other PAD leaders including Somsak Kosaisuk, Piphop Thong-chai and Somkiat Phongphaiboon did not respond.

Somsak said PAD's only goal at the moment was to oust Thaksin and they had not resolved how the post-Thaksin era should be.

The issue of "His Majesty's intervention", which Sondhi campaigned for during his anti-Thaksin talk shows, has been opposed by several key members of PAD because they do not want the return of the old days when the country was run by an absolute monarchy.

However, yesterday's campaign by Sondhi and Chamlong was the first call for royal intervention since the alliance launched its anti-Thaksin campaign early last month.

Earlier this month there were calls from academics, descendants of King Mongkut and King Chulalongkorn, senators and civic groups for His Majesty to appoint a prime minister to replace Thaksin.

But their petitions to His Majesty have not been answered.

Meanwhile, PAD spokesman Suriyasai Katasila did not confirm that protesters would go to Thaksin's home in Soi Charansanit-wong 69 to pressure him to make a "major decision".

The PAD rally yesterday went from Lumpini Park and down Silom Road to the Singapore Embassy.

When it passed the CP Tower, the headquarters of the CP Group, the Thai Rak Thai Party's key financial supporter, Sondhi told the crowd that the company's owner, Dhanin Chearavanont, conspired with Thaksin so his company could benefit from government contracts.

Shortly after the rally reached the Singapore embassy at about noon, the protesters sang the Thai national anthem in protest at Temasek Holdings' buyout of Shin.

Meanwhile, Thaksin cancelled trips to Pathum Thani, Ayutthaya and Angthong. He will reportedly preside over a TRT meeting today.