It doesn't help the Chancellor's cause that, by most accounts, we're going to get an unconvincing and unspectacular Budget – some spin about lower borrowing forecasts; none of the tax rises that Peter Mandelson has said we'll need eventually; and an insufficient bundle of spending cuts, centred around that old favourite, "efficiency savings". Chris Giles of the FT is already calling it a "Budget for losers". The losers, in this case, being Labour.
In which case, this could be a winning week for the Conservatives – and one of the most important in David Cameron's time as Tory leader. If they can deliver a sincere response to this latest political scandal, and continue with clear and punchy attacks on Labour's fiscal record, then the entire election campaign could tilt decisively in their direction. Stay tuned, so to speak.