Ed Balls has been savagely attacked by the press and business think tanks, following a pledge to re-introduce the 50p tax rate for top earners.
he media onslaught saw outraged commentary from across the centre-right press as well as pot-shots from Labour figures such as former City minister Lord Myners and allies of Tony Blair.
"It's absolutely not a return to the 1980s," Balls told the Andrew Marr programme.
"I was part of the government which worked closely with business. The reality is we're in different circumstances.
"To cut the top rate of tax when the deficit is still high is foolish and feeds resentment. I want to do the opposite: pro-business, pro-investment, pro-market - but let's get this deficit down in a fair way."
The Sunday Times branded the promise "suicidal for the British economy", while the Mail on Sunday said it was "a sad lapse into short-term, vote-catching irresponsibility" which showed Labour was returning to its "pre-Blair days of envy and spite".
The Sunday Telegraph said it "would send out the negative message that Britain penalises aspiration, enterprise and success".
Government spokespeople like chief secretary to the Treasury Danny Alexander and financial secretary to the Treasury Sajid Javid hardly had to even put out critical comments about Balls' plan, as business leaders and free market groups laid into the shadow chancellor with gusto.
The Confederation of British Industry (CBI) and the Institute of Economic Affairs (IEA) fired off attacks against the policy, while former Marks & Spencer chairman Stuart Rose said it would "risk confidence and investment".
More worryingly for Labour, the announcement triggered a backlash from prominent Blairites in the party.
"We need to encourage productive enterprise and effort rather than resort to predatory taxation," he said.
"The UK already has an income tax system that is more progressive than most of our international competitors."
A supporter of Blair told the Mail on Sunday: "This takes Labour back to the 1970s. It’s goodbye to the enterprise economy with knobs on.
'It is a return to the outmoded idea that you are for or against the poor. The whole point of New Labour was it showed you could help the poor and wealth creators at the same time.
"Miliband and Balls are turning their backs on that. The trouble is they are economically illiterate and have no understanding of business or profits."
But beneath the noise of the attacks on Balls, opinion polls showed huge public support for the move.
Even a poll in the Mail on Sunday, which has been particularly vociferous in its opposition, showed 60% of people agreed with it, with just 17% against.
"We'll get the deficit down in a fair way. That means those who the broadest shoulders bear their fair share of the burden," Balls said this morning.
"It would raise revenue. It would raise substantial amounts of revenue."
The 50p tax rate would cement the party's reputation as being more fair than the Tories.
It comes along with a mansion tax, rises in the pension age and the end of the winter fuel allowance for wealthy pensions.
Balls confirmed today that the party would not end free bus travel for pensions or reduced TV licenses, saying the latter scheme was so complex that "it's just not worth the candle".
Elsewhere in his speech yesterday, Balls pledged to begin cutting the national debt over the course of the next parliament.
Labour is now committed to running a surplus by 2020, just a year after the Tories, who are aiming for 2018/19.