Re: "You thought only Google dodges UK taxes? So do all the Brit firms"
If you look (I haven't), you may well find that Morrisons has a subsidiary in Gibraltar, a well known tax haven. The reason I think they might have a subsidiary there is because I know they have a store there.
There is nothing wrong with setting up shops in other countries, and if those countries don't want to collect tax on the profits made there, that is up to them.
As far as UK tax is concerned, a UK resident owner of an offshore company has to demonstrate that they have a legitimate business reason for setting up a company in that country, otherwise the profits of that company are taxable in the UK. In the Morrisons scenario, setting up a company in Gibraltar because you have a shop there is a legitimate business reason, so no UK tax would be payable on Gibraltarian profits.
Richard Branson has a hotel in the British Virgin Islands, the same rules apply there. He has a cable internet/TV company registered in New York, USA and an NHS Walk-in Centre business registered in Jersey. In both cases they were registered there because that's where the previous owners (NTL and Assura) set them up. There is no legitimate business reason for those companies to be registered there, so they do file UK tax returns.