Brown is initially uncertain of what to do, but his hand is ultimately forced when he is informed that several Labour MPs have threatened to defect to the Liberal Democrats – thereby eliminating Labour's razor-thin majority – if he fails to act.
Initially, Brown is indecisive about how to proceed, but he is ultimately driven to make a decision when he receives word that several Labour MPs are planning to defect to the Liberal Democrats, which would undermine Labour's narrow advantage in power and necessitate his swift action.