Shadow Chancellor George Osborne has rejected claims that the Conservatives are anti-business in a speech at the annual meeting of industry lobby CBI.
George Osborne insists the Tories are not anti-business
Mr Osborne is standing in for party leader David Cameron, who opted instead to visit British troops in Iraq.
He said the Conservative party was engaging with firms "as never before".
Prime Minister Tony Blair later stressed the need above all for Britain to think of its economy in global terms and remain "flexible and adaptable".
Mr Blair said economic issues which were once thought of in national terms needed now to be thought of in global terms.
Mr Cameron's absence has upset business leaders and disappointed the CBI.
"It is a paradox that, at the very moment when we have caught the political imagination of the country and we are engaging with individual businesses as never before, some claim that we do not understand the importance of business," said Mr Osborne.
The shadow chancellor stressed that the Conservative Party knew how important business was, and that without a strong and free economy little else could be achieved.
Placing the environment, social responsibility and flexible working hours at the heart of the political agenda was "not because we are somehow anti-business", Mr Osborne insisted.
The speech comes as the Tory party announced plans to impose a carbon tax on British businesses to encourage them to cut their CO2 emissions.
The party believes the proposal would raise more revenue than the existing climate change levy.
Following Mr Osborne's speech, Nick Cragg, managing director for Corus Engineering Steel, said: "We think it is a reasonable direction, but I think it has got to be balanced with the business message."
Mr Cameron is conspicuous by his absence
The decision to replace Mr Cameron with Shadow Chancellor George Osborne is likely to be seen by some as a rejection of business interests.
CBI president Sir John Sunderland said he was "disappointed" by the decision.
"It would have given him a chance to address some of the uncertainties about his position on a number of important business issues, so we see this as a missed opportunity," Sir John said.
Other attendees echoed this view. "My only response is, why did Cameron pull out," said one chief executive of a leading UK group, who declined to be named because the Tory party is one of his company's clients.
"We've come here to hear what he had to say, what he was going to do. He could have gone to Iraq any day. He's sending out the entirely wrong message by going to Iraq."
But a Conservative Party spokesman said David Cameron had not "snubbed" the CBI.
"The situation in Iraq is currently one of the most pressing issues that faces the country and it is essential that David Cameron, as leader of the Opposition, is fully informed of the situation on the ground," he said.
Earlier, the CBI published a survey which suggested that the UK's "burdensome and expensive tax system" had undermined the country's reputation as an attractive business location.
The business organisation polled top executives in 87 major firms and found that two-thirds were unhappy with the government's tax regime.
It was a major factor for the 20% of firms that had shifted some operations abroad and the 30% considering it.
However, the Treasury highlighted a report from consultants KPMG, which showed that the administrative burden of the UK's tax regime was 0.4% of economic growth, half that seen in the Netherlands.
The Treasury also said a World Bank survey found that the typical UK firm has the lowest tax level of all the G7 group of developed nations.
Speaking at the two-day CBI conference in London, Mr Blair reiterated that the impact of taxes on businesses was being looked into.
In reaction to the survey, Mr Osborne, said that he hoped to introduce measures to "radically simplify business taxes" with his very first budget, if elected.