Google insists that it pays its legally due taxes in the UK and HMRC appears to agree. Clearly the problem lies with the government. If Google conforms to the rules, and still the government insists that they are not paying enough tax, the solution is simple. Change the tax law.
I admit that I am not an objective observer. I, along with millions of others, benefit from the free use of Gmail. Google have digitized my first book, Henry's Trials; it is possible to read around 25% of it on line as a taster. Again, with no charge to me. Google has also digitized untold thousands of old books and made them available, free of charge, on line. This has helped my research enormously.
In short, I am a fan of Google. Whether or not the company is too powerful is a moot point. Most users of the Internet substantially benefit from its facilities. Let us have, by all means, an intelligent debate on the fair payment of taxes. But let us have no more of this nonsense about 'immoral', legal, tax avoidance.