Ed Balls has brushed off accusations that raising the top rate of tax to 50p is an anti-business move, as a second former minister from the last government accused the shadow chancellor of "lousy economics".

In the wake of criticism from companies, the senior Labour politician said the party was "pro-business" and emphasised that the higher rate of tax would only be temporary until the deficit was cleared.

Polls suggest raising the top rate is a popular move, with a Survation survey for the Mail on Sunday showing even 40% of Conservative voters support it, compared with 33% against. The poll of 1,000 voters found overall that six in 10 people backed the 50p rate, compared with one in five against.

However, it has met with a hostile reaction from business groups and two former Labour ministers, Lord Jones and Lord Myners, who said it was not a good economic move.

Lord Jones of Birmingham, who was a trade minister under Gordon Brown, said the policy would be popular but constituted another attempt to "kick" wealth creators.

The crossbench peer, who raised eyebrows when he addressed the Ukip conference this autumn, even predicted Balls would try to raise the rate further at some point, although the shadow chancellor denied that on Sunday.

"It's great politics but it's lousy economics," the businessman told the BBC's World This Weekend. "I learned a long time ago not to believe what politicians say but to watch what they do. It's their behaviour that tells you what they really believe. In the last few months we've got 'if it creates wealth let's kick it', really go for energy companies, really go for housebuilding, bankers, this time it's going to be high earners. Are we talking politics or are we talking what's right to create wealth and jobs in the nation?

"I'm not surprised at all, in fact I'm amazed he's going to keep it at 50p. I'd expect if he becomes the chancellor of exchequer we're going to be looking at 55-60p on the excuse that he gave today."

Earlier, Myners, a former Labour city minister who is also not affiliated, said the move would take the party "back to old Labour and the politics of envy".

"The economic logic behind Ed Balls's thinking would not get him a pass at GCSE economics," he said.

In contrast, the 50p top-rate plan was backed by the Labour former chancellor Alistair Darling, who said Balls was "quite right … to lay out these proposals here in relation to deficit reduction".

The shadow chancellor hit back at criticism on the BBC's Andrew Marr Show, saying it was the best way of getting the deficit down in a fair way to show everybody was playing their part in the recovery.

"I've had very many businesspeople say to me over the last year or so: 'We want to get the top rate of tax down' – well, of course they do. I want lower tax rates," he said.

"But they also say to cut the top rate of tax when the deficit is still high and when ordinary people are seeing their living standards fall is foolish and actually breeds resentment and I want to do the opposite of that. I want to say, look, pro-business, pro-investment, pro-market but pro-fairness. Let's get the deficit down in a fair way and make the reforms to make our economy work for the long term."

Balls also gave a staunch defence of Labour's record on the economy, saying there was no problem with public spending, the deficit or national debt before the financial crash of 2008.

In a challenge to the Conservative narrative about the causes of the economic crisis, the shadow chancellor said he was proud of Labour's public spending under the last government, which led to improvements in the NHS, schools and police.

Asked on the show whether he felt any regrets about Labour's spending, Balls said the party might have done some things differently but its level of expenditure was not the cause of Britain's recession.

"We didn't spend every pound of public money well, but to be honest with you, I'm really proud of what we did in the NHS, I'm really proud of the improvement in standards in schools, the extra police on the streets, what we did to tackle antisocial behaviour. We went into the crisis in 2007 with a lower national debt than we inherited and lower than France, Germany, America and Japan.

"There would be some spending things we wouldn't do, some spending things we would do differently, some areas we would spend more. But do I think the level of public spending going into the crisis was a problem for Britain? No, I don't, nor our deficit, nor our national debt. What happened was a global financial crisis which pushed up the deficit.

"The question then was: who can get the deficit down? George Osborne choked off the recovery, a recovery Labour had delivered, but it wasn't caused by public spending in Britain and that's just the truth."

Over the weekend, Balls also said he would run a budget surplus if Labour got back into power. However, he declined to say how the party would split its budgetary plans between raising taxes and cutting spending.

"We've said a mansion tax to cut the 10p rate for families. We've said that we would have to raise the 50p rate in the next parliament while we get the deficit down. We said there would be spending cuts, there would be rises in the pension age, we wouldn't go ahead with the winter fuel allowance for the richest pensioners, we would have a zero-based spending review," he said.

"But what I can't do is say what our tax policy and our tax decisions would be in budgets three years out when we don't know what will happen to the economy. But I'm clear: middle- and lower-income families are already paying a lot more tax, their living standards are falling, they're hard-pressed and they want help."

The foreign secretary, William Hague, criticised Balls's proposal, telling the BBC he believed the shadow chancellor was sending out the wrong signal about Britain.

He said: "I see as foreign secretary every day the rest of the world now seeing Britain with falling unemployment, with low inflation, with a real return of economic confidence. The long-term economic plan of this government is working.

"Ed Balls is sending the signal that if there was a Labour government we would go back to high taxing, high borrowing, high spending, and that is an anti-business, anti-job-creation agenda."