Labour was accused of downgrading its commitment to tackle global warming yesterday as Tony Blair and David Miliband, the Environment Secretary, were charged with reneging on a promise to introduce a Climate Change Bill. The claim, by the Liberal Democrats, came after the Government confirmed plans to consult on a "draft" environment Bill. The Bill was specifically listed in last year's Queen's Speech programme of forthcoming legislation after pressure from David Cameron's Conservatives and Sir Menzies Campbell's Liberal Democrats.