The Labour leader uses the Scottish First Minister's weapon of choice against him.
For the sake of a day of good headlines and a few billion pounds of extra tax, the Chancellor has put years of painful progress at risk.
Voters will still be worse off in 2015 than in 2010 - Labour's "cost-of-living" strategy remains its best hope of victory.
The Chancellor's cuts are likely to reverse the fall in inequality that he boasted of.
The Chancellor may have provided the Tories with the protective cover they need to limit universal pensioner benefits.
The Chancellor is forced to comment on the patronising image in every broadcast interview.
Osborne has failed to design the cap in a way that will advance structural reforms to housing and wages.
Party's decision could lead to backbench rebellion.
The UK is far more reliant than other European countries on social security spending to reduce child poverty.
"This is the Budget that confirms people are worse off under the Tories."
The Chancellor's offer to the over-65s is rational but crude politics: they vote more than any other age group.
A summary of George Osborne's fifth Budget.
Osborne should change the words we use to describe our taxes: National Insurance is Earnings Tax and Jobs Tax.
Including the level of the new welfare cap, another rise in the personal allowance, a deficit trap for Labour and some surprises.
The party says "It’s the same old Tory con – giving with one hand while taking away much more with the other."
We should actively encourage fathers and grandparents and ensure that they too have the social support to engage directly in the care of children.
The Chancellor needs to make it clear how national policy on jobs, housing and taxes will improve voters' personal situations.
The Foreign Office minister represents all of the groups the party needs to win over: women, ethnic minorities, northerners and Muslims.
On half of the 20 key tests of economic success, Britain is faring very poorly.
Rather than token announcements, the Chancellor needs to give much more meaningful power and autonomy to cities.
The parliamentary alliance between the the centre-right and the centre-left means the increase in the number of eurosceptic MEPs will have a largely symbolic effect.
Lord Oakeshott and the liberal Centre Forum are demanding a cut in the National Insurance threshold, rather than another cut in income tax.
The Tory Foreign Office minister backs Michael Gove and produces mock frontpage with the headline "Number 10 takes Eton Mess off the menu".
After four years of empty rhetoric, the best the Chancellor could do was to recycle an announcement from 2012 with a commitment to fewer homes.
The social consequences of inequality, such as reduced life expectancy and worse mental health, cost the equivalent of over £39bn every single year.
Just 15 per cent earn enough to pay the higher rate. Osborne is right to focus on helping the low-paid.
There was never a pure, unsullied left, seduced and corrupted by a power-hungry right.
Just as an independent Bank of England has helped ensure monetary stability, so a more powerful OBR could ensure fiscal sustainability.
The Labour leader is increasingly convinced not just of the moral and economic case for tackling inequality but also of the political case for doing so.
In the Ukraine, the Middle East and the eurozone, authority increasingly lies with elites, rather than elected representatives.