As the saying goes, you must walk before you can run. I think this is something former presidential candidate Tan Jee Say need to understand before he embark on his plan of forming a coalition of opposition parties.
The basic idea is sound and others like Chiam See Tong had tried it before but simply put; I think his plan is doom to failure.
The reason for my thinking is very simple; the various opposition parties in Singapore have nothing in common. For there to be a working coalition, there must be several political parties working together for a common goal. Currently the only thing the opposition has in common is that they have a common enemy in the ruling party, the People’s Action Party (PAP).
Outside that, they have nothing in common and having a common enemy is just not enough for the coalition to last. They need to have a common political goal or at least a policy that they can all agree on and build off. Until they find this common policy goal, the coalition plan will not work.