People are worried that with Blair in power the government will be pressured by Bush's troop surge in Iraq and won't keep its promise of bringing thousands of British troops home this year. Home from what many believe is an unwinnable war.
Blair staying in power but not really in charge puts the Labour party at a definite disadvantage. For one thing, it gives opposition MPs an easy target to aim criticism and ridicule at. Every day that passes without an announcement of Blair's departure means less time for the new leader to turn things around, more time for people to get even angrier as the dysfunctional government is exposed time and again, and more reason for opposition MPs to rub their hands together.
There is a program scheduled on British TV called the “Trial of Tony Blair.” In the program, Blair is convicted and jailed by a war crimes tribunal in The Hague. This is further evidence of UK sentiment about the Iraq war and Blair's part in it. The Labour Party needs to cast Blair from its neck before it is too late.