Balls and Miliband will come under ever greater pressure to say whether Labour will match the coalition's post-election spending plans.
A source suggests that Ed Balls's call for a temporary cut in the basic rate was designed to pre-empt Osborne's Budget rabbit.
The Chancellor will be forced to announce that the deficit will be higher this year and that the debt won't fall until 2018.
Support for Tory economic policy falls when Osborne's name is mentioned and support for Labour policy rises when Balls is mentioned.
If the Chancellor wriggles free again, Balls’s detractors inside Labour will be howling for blood.
Ahead of the abolition of the 50p tax rate on 6 April, Labour looks again to paint the Tories as the party of the rich.
If the party wants to attack Osborne on this territory, it needs to explain why and how it would borrow for growth.
Anthony Seldon's New Statesman column provokes debate.
It’s time the shadow chancellor fell on his sword, argues Anthony Seldon. Ed Miliband would be stronger for it, Labour would lose the taint of tax and spend, Yvette would be pleased . . . and even Balls might benefit.
Ed Balls set for revenge after 4G auction raises £1.16bn less than expected.