By Jonathan Head
BBC News, Bangkok
Former Thai PM Thaksin Shinawatra will return from exile on Thursday morning, according to his supporters.
Mr Thaksin has been living in exile since the 2006 coup
Mr Thaksin has been living outside Thailand since the military coup that deposed him in September 2006.
But he announced his intention to return after the party formed by his political allies won the general election in December.
He still faces a number of challenges, including an outstanding indictment for alleged corruption.
Mr Thaksin's 17 months in exile have done little to diminish his stature in Thailand.
For his diehard fans - and they number many millions - his return will be a moment to cherish, final confirmation that the generals who ousted him have failed in their ambition to kill his political career.
Mr Thaksin's equally passionate opponents have vowed to re-start their protest campaign that eventually brought about his downfall, although there is likely to be far less public appetite for that now.
Mr Thaksin is coming back earlier than expected, an indication of the growing disarray in the government led by his allies.
His choice of party leader, Prime Minister Samak Sundaravej, is proving to be a public relations disaster.
Mr Samak recently denied a well-documented massacre of students in 1976 by right-wing vigilantes.
He also downplayed the deaths of 78 Muslim demonstrators in army custody three years ago.
Both comments have provoked a storm of protest, and there are also deep rifts between some of the key factions in the governing party.
Only Mr Thaksin, the party's main financier, has the authority to impose discipline on the cabinet.
But there is a risk he will be tempted to get too involved.
He is still subject to a five-year ban on holding political office, and viewed with deep suspicion by the military and much of the traditional elite.
He must also deal with an outstanding charge of corruption against him, although with the dramatic shift of power to his allies this year, the will to pursue the case through the courts may well evaporate.