SCENARIOS: What's in store for politically riven Thailand?

By Ed Cropley

BANGKOK (Reuters) - Political tension has returned to Thailand after a brief lull for a royal cremation, with a grenade killing one anti-government protester on Thursday and wounding 23, teeing up another confrontation with police this weekend.

Sunday's planned march on parliament by the People's Alliance for Democracy (PAD) is likely to be a flashpoint, especially if protesters blockade the building to prevent an important session on Monday.

An identical blockade on October 7 led to running street battles between police and protesters in which two people were killed, and hundreds, including scores of police, were injured.

Whatever happens, Thailand is likely to remain divided between the rural and urban poor who support Thaksin Shinawatra, ousted as leader in a 2006 coup, and the Bangkok middle and upper classes, loosely represented by the PAD, who despise him.

The elected administration, which is accused of being a Thaksin puppet, has been working out of temporary offices in an old airport since the PAD overran Government House in August.

It has all but given up on policy-making, intensifying investors' concerns about the export-dependent economy's ability to cope with global recession.

The following scenarios examine what might happen next:

MESSY SUNDAY

- Unless one side backs down -- and there are few signs they will -- Sunday/Monday is likely to be messy. The PAD's stated intention is to trigger a coup and anarchy is its main weapon.

Police will be mindful of last month's high number of casualties, especially the protesters who lost limbs from exploding tear gas grenades, and are likely to be more cautious.

However, hardline PAD elements are armed, and shot at police lines last month. If any officers are shot dead, it is not hard to see their colleagues responding in kind.

All bets are off if a full-scale shooting match breaks out.

RECRIMINATIONS FLY, CRISIS RUMBLES ON

- Whatever happens on Sunday/Monday, accusations will fly from both sides, ensuring the crisis rumbles on amid a poisonous political atmosphere.

There is bound to be a small lull around the king's birthday on December 5, but tensions will rise ahead of December 13 when the exiled Thaksin holds a "phone-in" to a sports stadium rally.