Google's executive chairman Eric Schmidt said the company pays "the mandatory amount" in tax and denied that a legalistic approach to paying taxes did not sit well with the firm's pledges on social responsibility.
He told BBC Radio 4's Start the Week: "I do not agree with this and the reason is that at least under American law we have a fiduciary responsibility to our shareholders to account for things properly.
"So if we were, for example, to just arbitrarily decide to pay a different tax rate than we were required to, a more favourable one for example to a particular country, how would we account for that?
"How would we file the necessary paperwork, what would be the legal consequences in other countries?
"Somehow these questions are ignored in the debate. We are very happy with whatever the countries all come to agreement on. We are not particularly upset about it."
He added: "Our position is very simple, taxes are not optional, we pay the mandatory amount."