It can come as no surprise that the red shirts plan to rally at Sanam Luang, what is crucial here though is that it puts the army and police in a very delicate situation.
If the rally turns even remotely violent then the police or military have two choices: first, they respond with force. This will play into the hands of the reds' leaders, who can then expose the double standards of the authorities. This will further expose and pressurise the people behind them, all the while raising the indignation of not just the reds but also neutral observers.
Option two is to do nothing again. This will simply cripple the new government just like the old one, and also make people wonder just what the heck the military and police need such a huge budget for, if they do absolutely nothing. We would all hope the reds make a peaceful, democratic protest, but given their anger this may be asking a lot.
Is there anyway out of this predicament?
As an interesting aside it appears that UK politics and Thai politics are forming some friendships. PAD figures apparently met with a Liberal Democrat MP last month and Aphisit is a good friend of eccentric London Mayor and prominent Conservative member Boris Johnson. (h/t to Bangkok Pundit and Thai politico for these facts). Here is a clip of Boris at his best.