The prime minister accused the likes of Starbucks, Amazon and Google of lacking "moral scruples" by seeking ways to minimise their tax payments to the exchequer.
Cameron's comments to business leaders and young entrepreneurs in Preston came weeks after MPs on the public accounts committee accused the three companies of immorally minimising their UK tax bills by using secretive jurisdictions and complex royalty payment structures.
"We've got to crack that [tax evasion by multinationals]," Cameron said in response to a businessman's question about why big foreign companies have been allowed to get away with paying next to nothing in tax.
"I want to make damn sure that those companies pay it. It's simply not fair and not right what some of them are doing by saying: 'I've got lots of sales in here in the UK but I'm going to pay a sort of royalty fee to another company that I own in another country that has some special tax dispensation.' "
Cameron claimed he was going to put tax avoidance "right at the top of the agenda" of the UK's presidency of the G8. "I'm chairing the G8 this year so I'm going to be getting the Americans and the French and the Germans and the Italians and the Japanese all to look at this together – how can we try and stop unfair tax farming practices."
Cameron said some companies had told him that their "really aggressive tax avoidance" was all within the law.
"Well, actually there are lots of things that are within the law but we don't do because actually we have some moral scruples about them and I think we need this debate abouttax too. I'm not asking people to pay massive rates of tax."
Last month, Starbucks offered to pay a "voluntary" £20 million to HM Revenue and Customs following intense criticism after it was revealed the giant US coffee chain had paid just £8.6m in UK corporation tax over the past 13 years, when it had made sales of £3.1bn.
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