AS well-travelled as Scots tend to be, it is a fair bet that Luxembourg is not high on many "must-visit" lists.

Pity, really, as its attractions are numerous and varied. From strolling along the Pont Adolphe en route to a fabulous faux-peasant cuisine lunch, followed by a visit to the Palais Grand Ducal to admire its frontage, Luxembourg has its charms.

Still, we can at least comfort ourselves with the knowledge that while we may not have come within a sniff of the Grand Duchy, our money has a high old time there.

Courtesy of an international tax system that gives shelter to the profits of multi-billion earning companies, any money you have sent Amazon's way lately – that birthday book for mum, the DVD for the nephew, a treat for yourself – has gone via Luxembourg, where the tax rate is under 6%. If the money had stayed in Britain, tax would have had to be paid at 24%.

As the Public Accounts Committee of the House of Commons has been hearing again this week, such arrangements are perfectly legal. You may recall that late last year a host of multinationals, including Amazon, Google, and Starbucks, were called before the PAC to explain why they earned billions in profit from the UK yet paid just millions in tax.

The evidence sessions provided fascinating lessons in how global capitalism, particularly among companies which traded on their reputations for being responsible, ethical, go-ahead, 21st century and all that other modern mood music jazz, were in fact as concerned with the bottom line as any of their 19th-century counterparts. While no company engages in such outrages as sending children up chimneys, they certainly like to send their money on long trips. Just as well money never sleeps.

An outcry duly followed, with the PAC chair, Labour MP Margaret Hodge, denouncing the actions of such firms as "immoral" and consumers murmuring about boycotts, or quietly staging them. Several months on, some of the firms are back before the PAC, or filing accounts, and the revelations keep on coming.

Both the scale of the avoidance problem, and the extent to which multinationals benefit from operating in the UK, are becoming clearer by the day. It emerged this week, for example, that Amazon UK enjoyed sales worth £4.2 billion last year. On this, it paid tax of £2.4m. At the same time, the British taxpayer handed the company £2.5m in grants to expand its operations in Scotland, among other things. One does not have to buy a copy of Accounting for Dummies from Amazon to see that the firm got more out of the UK in grants than it paid in corporation tax. Still, a real head-scratcher, that one.

What happens at Google provokes similar puzzlement. At yesterday's PAC hearing there was a through-the-looking-glass argument between several MPs and Google, much of it bad tempered, about whether the firm sold advertising in the UK and would therefore have to pay UK corporation tax rates. No, said Google. Though there are sales staff in Britain the money goes to Dublin, where the firm has its European headquarters and employs 3000 staff, so Irish tax rates apply. The Irish tax rate, surprise, surprise, is lower.

The MPs huffed and puffed but they could not blow the man from Google down. They failed to do so for the very good reason that, on paper, the firm is doing nothing wrong. The likes of Amazon and Google are internet companies dealing with a UK tax system that has simply not kept up with the internet age. While these firms are on superfast broadband to ever bigger profits, dear old HM Revenue & Customs is stuck on dial-up, trying and failing to catch up. They are the hares, the tax man is the tortoise. It is not just a UK problem, but an international one, and it will require an international solution.

But it could take years for governments to agree among themselves, and on past performance who would trust our here-today, gone-tomorrow elected administrations to do so? Too many governments, as can be seen from the British grants to Amazon, are understandably concerned with keeping jobs in the here and now than offending multinationals and jeopardising their own chances at the ballot box come election time. Pursuing firms too aggressively on tax runs the risk of firms quitting these shores for elsewhere. If they can shift money around at the click of a mouse; jobs can follow just as easily. That would harm the tax take in other ways. Multinationals may not pay tax at rates we would like them to, but their staff do.

Governments, including our own UK Coalition, talk the talk on tax avoidance by multinationals but they are not serious about fighting the good fight, otherwise action would have been taken by now. Locked in an austerity mindset, mindful that they need to get more people into jobs, they are not about to start a commotion any time soon.

This is not to say, however, that nothing can be done in the short term. Margaret Hodge is not alone in arguing, as she did yesterday, that HMRC needs to up its game. After all, they are quick to go after individuals and small businesses with all the speed and ferocity of velociraptors. When it comes to the big boys, however, they appear to act more like huge, lumbering, gums-grinding herbivores.

HMRC has strongly rejected such criticism in the past. Yet e-commerce did not start yesterday, multinationals did not begin setting up HQs in low-tax countries a week ago. Surely it should be a chief part of HMRC's duties to stay ahead of the game and not be just another follower?

That the tax affairs of Google, Amazon, Starbucks and the rest are now up for discussion is due not to the Government but to the PAC, campaign groups such as UK Uncut, the public and the press. Given the lack of action on the part of our own Government and others, the initiative will have to remain with this quartet. That is no bad thing, for the moment at least.

Consumers in particular hold a lot of power here, and it is they who are most affected by big companies paying relatively small tax bills. Every penny not paid in UK tax is one less penny to spend on UK schools, hospitals and the rest. Making most UK companies pay full corporation tax, while some pay smaller amounts elsewhere, puts other jobs and firms at risk.

When it comes to tax it is consumers, and companies who pay their fair share, who really are all in this together. It is high time the low-tax-paying rest joined us.