LABOUR will restore the 50p top rate of income tax for high earners if it wins the 2015 General Election, Ed Balls said yesterday, prompting a wave of criticism from business leaders.

As part of Labour's effort to reconnect with voters struggling with the cost of living, the shadow chancellor said the richest 1%, those paid more than £150,000 a year, would be asked to pay extra to help cut the deficit.

Labour raised the top rate of income tax from 40p in the pound to 50p in 2010, but the Coalition cut it back to 45p last April.

Chancellor George Osborne was attacked for cutting taxes for millionaires while slashing benefits for the poor, but defended the decision by saying the 50p rate depressed Treasury income by £100 million, rather than raising more money.

However, Balls claimed yesterday that new figures showed those earning over £150,000 had paid "almost £10 billion more in tax" in the three years when the 50p rate was in force.

Speaking to the Fabian Society annual conference in London, he said a future Labour government would demonstrate fiscal discipline by having a legally binding pledge to balance the books and close the UK's £100bn deficit by 2020.

He said: "When the deficit is still high, when for ordinary families their real incomes are falling and taxes have risen, it cannot be right for David Cameron and George Osborne to have chosen to give the richest people in the country a huge tax cut.

"For the next parliament, we will restore the 50p top rate of tax for those earning over £150,000 - reversing this unfair tax-cut for the richest 1% of people in the country and cutting the deficit in a fairer way."

He also pledged that Labour would expand free childcare for working parents to 25 hours a week, force the long-term unemployed to take a job or lose benefits, and set up a British investment bank to support small businesses.

The tax pledge was welcomed by trade unions as a move towards a fairer system, but denounced by the Coalition parties as evidence of Labour's inherent recklessness with the economy.

Sajid David, the Tory financial secretary to the Treasury, said: "Labour got us into a mess by spending too much, borrowing too much and taxing too much. Now Ed Balls is proposing more spending, more borrowing and more taxes.

"Labour would put the recovery at risk, drive away investment and put our economic security at risk. That would put the financial security of hard-working people and their families at risk."

LibDem Chief Secretary to the Treasury Danny Alexander said: "Labour's hypocrisy on taxation is breathtaking. In government they left a system full of loopholes for the wealthy to exploit."

A spokesman for the Unite union said the 50p pledge showed Labour understood the need for a fairer tax system. He said: "This is a beginning. We would urge Labour to also tackle the disgraceful abuse of the system by the evaders and avoiders too. Voters will know now that Labour is emerging as a positive choice for this country.

"Contrast this move with the complacency of the government, which, instead of finding ways to get money into people's pockets, insists that everything is rosy to cash-strapped workers."

Business leaders, many of whom would face larger personal tax bills, claimed a return to the 50p rate would derail the entire UK economy.

Rob Templeman, chairman of the British Retail Consortium, said: "This tax increase would be bad for business in Britain. It would put the recovery at risk, deter investment and ultimately cost jobs."

Sir Stuart Rose, chairman of Ocado, said: "This will put at risk all the good work that has been done to put the economy back on track."

Simon Walker, director general of the Institute of Directors, accused Balls of "pandering to the troglodyte elements in his own party".