In a scathing report, the House of Commons Public Accounts Committee dismissed as "deeply unconvincing" Google's claims that its UK sales activities take place in low-tax Ireland and found that the company's account of its operations made "absolutely no sense".
Committee chairwoman Margaret Hodge branded the company's arguments "brazen" and said the only way for Google to repair its damaged reputation was to arrange to pay a fair share of tax in the countries where it earns its massive profits.
But the report was also highly critical of tax authorities, finding it was "extraordinary" that HMRC did not challenge Google over its arrangements. The cross-party committee also warned that the UK's big accountancy firms had damaged their reputations by helping big business clients avoid tax, calling on them to recognise that "the public mood on tax avoidance has changed".
The committee urged the Government to take a lead internationally on modernising "out-of-date" tax frameworks covering internet-based commerce, and commended Prime Minister David Cameron for putting tax avoidance at the heart of his agenda for next week's G8 summit in Northern Ireland.
But Mr Brittin was hauled back in front of the committee in May to face a second grilling over evidence from whistleblowers which showed "clear discrepancies" with his claim that none of Google's 1,300 UK staff were working in sales. At that hearing, Ms Hodge questioned Google's famous "don't be evil" motto, telling Mr Brittin: "I think that you do do evil, in that you use smoke and mirrors to avoid paying tax."
A Treasury spokesman said: "This Government is committed to creating the most competitive corporate tax system in the G20, but this goes hand-in-hand with our call for strong international standards to make sure that global companies, like anyone else, pay the taxes they owe. The UK, along with Germany and France, has since last year been leading the efforts through the OECD to modernise the international tax rules and we have put tax and transparency at the heart of the G8 agenda which we will chair next week."
A Google spokesman said: "As we've always said, Google complies with all the tax rules in the UK, and it is the politicians who make those rules. It's clear from this report that the Public Accounts Committee wants to see international companies paying more tax where their customers are located, but that's not how the rules operate today. We welcome the call to make the current system simpler and more transparent."
HMRC head of business tax Jim Harra said: "Since 2010 we have collected over £23 billion in extra tax through challenging large businesses' tax arrangements. Through tackling transfer pricing issues, we have collected £2 billion since 2010 alone. We relentlessly pursue businesses who don't play by the rules, these results reflect this."