Business chiefs have accused Ed Miliband of trying to close down debate about Labour's policies by launching a personal attack on the Boots boss who suggested it could be a "catastrophe" if he became prime minister.
The Opposition leader vowed yesterday to "stand up to these powerful forces" and accused the Monaco-based Stefano Pessina of being part of an "unholy alliance" with the Conservatives against change.
Labour has mounted a fightback after the veteran Italian executive said the party's wider platform was "not helpful for business, not helpful for the country and in the end it probably won't be helpful for them".
Voters would not "take kindly to being lectured by someone who is avoiding his taxes on how they should be voting in the UK general election," Mr Miliband suggested.
But his comments were criticised as a "pretty unattractive" attempt to silence critics and which "smacked of the destructive anti-business mood that went out of political fashion decades ago".
Labour painted the attacks as a co-ordinated Tory operation, pointing out that among those at the forefront were a Conservative peer, a party donor and another who was knighted under David Cameron.
Among the most vocal was former Marks and Spencer boss Stuart Rose - once a member of Gordon Brown's business council and given a life peerage last year by the Prime Minister.
Lord Rose defended Mr Pessina's right to speak out and said Mr Miliband had "blown apart" decades of political consensus that the business sector should be cherished as an engine of growth, to return to 1970s-style Labour policies.
Writing in the Daily Mail he said: "As a man responsible for 70,000 workers - that's 70,000 livelihoods supporting 70,000 families - Mr Pessina was perfectly entitled to speak out.
"What happens in Westminster has a direct impact on his employees and his customers."
Business craves "certainty" he wrote, but Labour had engaged in a "steady drum-beat of anti-business policies" such as tax rises and "lacks a clear and credible plan" to deal with the deficit.
'Danger of resorting to abuse'
He drew a parallel with the threat by one nationalist politician in Scotland that firms which backed the "no" campaign would face a "day or reckoning" in an independent Scotland.
"It underlined the danger of resorting to abuse and personal attacks when people raise genuine concerns. In a healthy, thriving democracy, people must be free to speak out without fear or favour," he said.
"This is the real face of British business. They aren't the enemy. They are the backbone of our economy - and they deserve the support and respect of our politicians."
Other senior corporate figures defended the right of the business sector to make its views known, whether or not the bosses concerned were UK voters.
Former B&Q chief Sir Ian Cheshire told The Telegraph that "personal attacks are pretty unattractive".
He said: "It has got to be legitimate for business leaders who are involved in big business in the UK even if they are not UK citizens to have a view on the likely impact of elections because this is a national debate.
"He has the complete right to have his say, as have other people.
"Even if you disagree with him, I don't think it is necessary to have personal attacks on Stefano in this way - particularly for a guy who has really ploughed a lot of money into the UK and is doing now to make Boots a world force."
Heathrow airport chairman Sir Nigel Rudd said: "Making personal attacks on people stifles debate. It makes people think twice about voicing their opinions.
"We should listen to all opinions especially people who have created as many jobs and are as astute as Stefano Pessina.
"I would not make personal attacks on union leaders either if they had a view that I agree with or disagree with. We should encourage people to enter the debate."
Walgreens Boots Alliance insisted Mr Pessina's comments had been "taken out of context", and that he was expressing personal views and "not campaigning against Ed Miliband or the Labour Party".
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