Why Google's UK boss is facing tough tax questions from MPs

Search online for a company that has been caught up in the political crossfire over the amount of tax they pay, and the name of the business you're using to use to hunt out information will probably pop up itself.

And Google will be under the microscope once more when its UK boss is summoned again by MPs. At the end of last year, Matt Brittin answered questions smoothly and politely when under interrogation by Margaret Hodge, the determined chair of one of Westminster's most powerful committees.

But she has more questions for him now on quite a particular point. Back in November he told MPs that people buying things - mainly advertising - from Google were sold products by Google in Ireland.

He said staff in London might help that process along, but Ireland was where deals were done. That is where Google Europe is based - where financial transactions are accounted for.

That is important because tax is paid in the country where a business' books are based, and that is what has led to accusations that Google don't pay their fair share.

Since then though there have been claims that staff at Google's swanky London HQ do more than just encourage or advise, and in fact a normal sales team is based there, operating just like in any UK based company.

One former staff member there told me: "It worked exactly like every other sales job I had."

Google insists that is not the case. While UK staff are part of the sales process, they do not do the deals, they say. It is not likely that Brittin will shift from this position, but it is likely that MPs will be dubious about his explanation.

If someone is paid in pounds, is paid commission and bonuses for business they bring in, can they really be said not to be in sales?

Technically, Google will insist they absolutely can, 'digital consultants' the name they give those staff. A company as well funded and careful about its image as Google is very unlikely to be found to have broken the rules.

But expect a lively morning at the committee which, whatever the rules and the law says, is likely to push Google hard.

While you may not like the fact that some firms use accountants and lawyers to push the regulations to the limit, and many businesses don't like it either, it is worth remembering that it is the politicians, not the companies themselves who set the rules.

By chance a judgement is also expected in the morning at the High Court. The campaign group UK Uncut has been going after the bank Goldman Sachs, claiming they have been not paying their fair dues.