Bangkok  - Thousands of so-called Red Shirts - supporters of fugitive former premier Thakisn Shinawatra - marched on Government House in Bangkok Thursday in an effort to force the current administration from office.

As estimated 30,000 protestors left Sanam Luang, the Royal Grounds, a traditional launchpad for anti-government demonstrations, and marched towards Government House - the seat of the current cabinet led by Prime Minister Abhisit Vejjajiva.

Some 7,000 soldiers and police were stationed around Government House to prevent the Red Shirts from occupying the compound, like the so-called Yellow Shirts did last year.

The Yellow Shirts, or the People's Alliance for Democracy, a loose coalition of groups adamantly opposed to a return to power of coup-ousted populist premier Thaksin, occupied Government House for four months in 2008, leaving the previous pro-Thaksin administration without permanent offices.

The Red Shirts, who are as fanatically pro-Thaksin as the Yellow Shirts were opposed to him, are unlikely to occupy Government House in their bid to topple the current administration.

Abhisit has urged the protestors to abide by the law and avoid violence.

The highlight of Thursday's protest is expected to be a phone-in address by Thaksin from abroad at 8 pm (1300 GMT).

Thaksin, who faces a two-year jail sentence in Thailand on abuse-of-power charges, has been addressing the Red Shirts on an almost nightly basis in what is seen as an increasingly desperate effort to galvanize his anti-government mass movement.

"The Red Shirts need to be boosted," said Jakrapob Penkair, a key Red-Shirt leader.

Thaksin has vowed to disclose who was behind the military coup that toppled him on September 19, 2006, ending his five years as prime minister.

In an address to his supporters on Sunday, Thaksin accused several high-ranking members of the Privy Council to Thai King Bhumibol Adulyadej of being directly involved in the coup plot.

The accusations are sensitive in that they imply the close advisors to the king have become involved in politics.

"Thaksin is playing a game of brinkmanship to persuade people who are wavering over to our side," Jakrapob said.

Others believe Thaksin's provocative remarks are a sign that he is becoming politically desperate.

"Probably he is panicking, thinking it is now or never," said former close ally to Thaksin who asked to remain anonymous.

Thaksin has been in self-exile since August 2008. The government has frozen about 2 billion dollars of his family's cash in Thai banks.

The pro-Thaksin Peau Thai opposition party earlier this month failed to win a no-confidence motion against Abhisit and five cabinet members. In fact, five members of the Peau Thai even voted with the government, suggesting growing splits within the party and pointing to Thaksin's weakening grasp over his political nominees. (dpa)