The bosses of some of Britain's largest multinational corporations have urged David Cameron to stop moralising and rein in his rhetoric on tax avoidance ahead of a G8 summit next month. 

Chief executives of companies such as Burberry, Tesco, Vodafone, BAE Systems, Prudential and GSK were keen to take a final opportunity to lobby the prime minister in advance of the meeting of political leaders in Northern Ireland. 

Cameron has pledged to use Britain's G8 presidency to tackle aggressive tax avoidance by multinationals, but is also keen to heed the counsel of his business advisory group, which he met with on Monday. 

Also present was Google's chairman, Eric Schmidt, despite the internet search firm coming under fierce attack from MPs last week because of its tax arrangements. 

The president of the Confederation of British Industry, Sir Roger Carr, who was at the meeting, was among those who have taken issue with Cameron's attacks on the ethics of big business tax engineering. 

During a speech earlier in the day at a London event organised by Oxford University's Said Business School, Carr said: "It is only in recent times that tax has become an issue on the public agenda – Starbucks, Google, Amazon – businesses that the general public know and believe they understand; businesses with a brand that become a perfect political football, the facts difficult to digest; public passions easy to inflame." 

In what appeared to be pointed criticism of increasingly firm rhetoric from Cameron on multinational tax engineering, Carr insisted tax avoidance "cannot be about morality – there are no absolutes". 

In January the prime minister used a speech at the World Economic Forum in Davos, Switzerland, to put a marker down on questions of tax structuring by big business. " Some forms of avoidance have become so aggressive that I think it is right to say these are ethical issues," he said, urging multinationals to "wake up and smell the coffee". 

Carr said: "Tax payments are not, and should not be … a payment viewed as a down payment on social acceptability, or a contribution made by choice in order to defuse public anger or political attack." 

The CBI boss, who is being talked of as a successor to Dick Olver as chairman of BAE Systems, invited the G8 to consider three points in relation to tax reform:

• Avoiding the moral debate – "it's all about the rules". 

• Fixing the rules on an international stage, not unilaterally. 

• Consulting on proposed changes with business. 

A Downing Street spokesman said the specific controversy generated by Google's tax affairs was not raised during the meeting with business leaders, though discussions did focus on "explaining the tax and tax transparency part of the G8 agenda". 

Also speaking at the Said business school event was Margaret Hodge MP, chair of the public accounts committee and one of parliament's most outspoken critics of tax avoidance.  With Starbucks and the big four accountancy firms in attendance, she said: "Your time has now come on accountability.  You are now being asked to answer certain questions and it's important that we all engage. 

"One could argue that the way some companies organise their affairs is anti-competitive to many British companies.  Especially if you look at the way Amazon arranges its affairs." 

On Revenue & Customs' appearance before her committee last week, she added: "Their approach, when they came to parliament last week was complacent and patronising, an attitude that actually didn't help take the committee forward.  I don't think it helped members work closely together across my committee. 

"In my opinion they are not aggressive enough.  These are issues of how you judge individual companies, but at the moment I'm not clear how HMRC makes its judgments.  So toughen up, HMRC." 

Other attendees at the event were representatives of retailer Marks & Spencer, which was accused of running its online business in a similar structure to Amazon's, and pharmacy group Alliance Boots, which recently relocated its headquarters to Switzerland.