Thaksin has been found guilty on conflict of interest charges and is a fugitive from justice. He would want an amnesty for himself and for allies who have been banned from politics for electoral fraud and other offences. It would be difficult to get that through the courts.

WHO IS PREM?

The demonstrators have also targeted Prem Tinsulanonda, marching to his house and demanding that he resign, like Abhisit.

Prem, 88, is a former general and prime minister. More importantly, as head of the privy council he is the chief political adviser to the king.

Thaksin has named him in recent days as a behind-the-scenes instigator of the 2006 coup, breaking a taboo.

"The Privy Council is an institution traditionally looked up to as representing the king, and before this protest there was hardly anyone attacking it directly," said Professor Lae.

"I think the majority of Thais still have this same feeling and this strategy will backfire in the end."

WILL ALL THIS HURT THE ECONOMY?

The economy is already on the ropes, likely to shrink as much as 4 percent this year, according to the International Monetary Fund, because of a slump in exports and the effects of last year's unrest, which hit tourism badly.