Ed Miliband was facing a backlash from industry last night after he promised to tackle predatory practices in big business.
He faced fire over his conference broadside in which he vowed to rein in the excessive pay in the top echelons of industry and break up business cartels that drive up prices.
The Labour leader won applause in Liverpool for a crowd-pleasing attack on "asset-strippers" and the "fast-buck culture of the past 30 years".
He insisted in a series of interviews yesterday that he was not "anti-business" but wanted to champion "responsibility in the top of our society". Labour sources said his comments were evidence of his determination to challenge the 30-year-long political status quo under which sharp practice was not challenged.
The counter-attack was led by Lord Digby Jones, the former head of the CBI and a trade minister in Gordon Brown's government.
Lord Jones said the conference speech decisively demonstrated the Labour leader was not pro-business, labelling his speech as a "kick in the teeth for the only sector that generates wealth, that pays the tax and creates the jobs this country needs".
He added that Britain needed leaders rather than people "playing to a union gallery".
The former Labour chancellor, Alistair Darling, also cast doubt yesterday over the language used by the party's leader. He asked: "If I build in a city centre, am I good for investing or bad for speculating? Businesses are there to make money."
John Cridland, the current director-general of the CBI, said: "With growth weak, Ed Miliband is looking for a new business model, but he must be careful not to characterise some businesses as asset-strippers.
"We need businesses to create the wealth and jobs upon which our country's economic recovery will depend."
Andrew Cave, of the Federation of Small Businesses, protested that Mr Miliband's call to force companies who wanted to bid for public contracts to provide apprenticeships "risks clobbering small business and cutting off a lifeline for them".
A software entrepreneur accused the Labour leader of simplistic thinking. Mike Lynch, the chief executive of Autonomy Corporation, told the BBC: "You can't but like the idealism in the speech, but the reality is that it isn't like a Saturday morning cowboy matinee where you have the guys in the black hats and the guys in the white hats."
He added: "Presumably you would have to set up a new department of civil servants to decide whether a business is good or bad so you can decide what the tax rate is. What is an asset-stripper and when is an asset-stripper a recycler?"
As the criticism mounted, Mr Miliband was asked whether his comments about business practices showed he was leading his party to the Left. He responded: "Absolutely not. We are going to be firmly in the middle ground of politics, but the middle ground is changing.
"The idea that we should have responsibility in the top of our society ... it is not a left-wing idea to say that there should be responsibility there. It is absolutely in the middle ground. It is absolutely about the values of the British people, which say everybody should show responsibility.
"Equally, I talked very frankly in the speech about how we need to change the benefit system. There are too many people taking something for nothing."
He also attempted to repair some of the friction within the party caused by the catcalls which greeted Mr Blair's name in his speech. Mr Miliband said: "It's not a jeer I share."
The Labour leader said last night that he would not try to abolish private schools or remove their privileged tax status, despite his promise to "break the closed circles" which give some people more opportunities than others.
He told Channel 4: "It is very difficult to take away the charitable status for a whole host of complicated reasons. I don't think you can abolish public schools in a free society. Am I going to abolish public schools? No."
He added: "We do need to change the way the class system works. We do need to open it up."Reuse content