From her sensible trousers to her permed hair, Punyanuch Promsiriyat, 57, is the very image of a People Power revolutionary. Dictatorships all over the world have been brought down by people like her — respectable, middle-class citizens dedicated to democracy and justice.

Mrs Punyanuch, a shopkeeper from Bangkok's suburbs, has a flag, a T-shirt with a slogan and a cause: the People's Alliance for Democracy (PAD).

For ten days thousands of its supporters have occupied Government House in Bangkok, demanding the resignation of the Thai Prime Minister, Samak Sundaravej. Students, pensioners and ladies like Mrs Punyanuch have camped out here in pursuit of change.

But this is a “people power” movement like few others. Its bête noire, Mr Samak, is a legitimately elected leader who was voted in just nine months ago.

Far from demanding more democracy, it is calling for a restriction of voting rights. Despite its claim to be a peaceful movement, this week the PAD's campaign turned deadly.

“The PAD gives democracy a bad name,” Sunai Phasuk, of Human Rights Watch, said. “It's not about democracy, it's about narrow nationalism. It could turn back the clock and make the progress Thailand has made in the last two decades meaningless.”

The movement began two years ago during the Government of Thaksin Shinawatra, the most popular — but also the most divisive — Prime Minister Thailand has had. His healthcare schemes and programme of cheap loans won him the love of rural Thais long ignored by the political class, and took him to three successive victories.

Middle-class urban voters abhorred him, accusing him of using the wealth he acquired as a businessman to corrupt Thailand's institutions and make it impossible to unseat him.

The PAD is a coalition of businessmen, activists and grassroots organisations from left and right, led by a Thai media mogul named Sondhi Limthongkul. After months of rallies Mr Thaksin was deposed in 2006 and fled to Britain. The PAD disbanded.

After a year of military rule an election was held — and won by Mr Samak, a self-declared follower of Mr Thaksin. In May the PAD re-formed to oust him. Protests climaxed last week when thousands of its members pushed past the police and occupied Mr Samak's office.

The “Last Battle”, as its leaders call it, has exposed the PAD's darker side. Its insistence on the rule of law looks ironic, given its actions: the occupation of the centre of government in defiance of arrest warrants issued against its leaders. Its original call for the head of Mr Samak has broadened to a demand for veto power over the Government.

In July it announced a “New Politics” that would reduce the number of elected MPs to 30 per cent, with the rest appointed by business and trade organisations.

Its biggest rhetorical difficulty is the inconvenient truth that, whatever their shortcomings, Mr Thaksin and Mr Samak were chosen by democratically elected parliaments. The latest proposal is to put the question of Mr Samak's survival to a referendum, something the PAD is unlikely to accept.

There is little sign of compromise, strong signs of further violence - and of the moral purity of people power, no sign at all.

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