If the law specifically allows something then it's not a loophole

Yet another whine about how Uber is doing something or other:

Uber has been accused of exploiting a legal loophole that allows its drivers to operate in UK towns and cities where they don’t have a licence, leaving local authorities powerless to regulate them.

Mick Rix, the GMB union’s national officer for the hackney and private-hire taxi trade, said the company behind the cab-hailing app was “acting with impunity” across the UK, where it was increasingly “spreading its tentacles” into smaller towns and cities.

What is happening is that if you've a license from anywhere then you can work anywhere. As opposed to the former system where you could drop off anywhere but only pick up in that local authority that you were specifically licensed in:

After changes to the law surrounding taxi licensing, brought in by the Deregulation Act 2015, drivers with a private-hire licence from a local authority can use it to operate anywhere in England and Wales. Previously, the law required drivers to return to the area in which they were licensed between jobs.

The law was specifically changed to allow this. This is not therefore a loophole. Except if we are to assume that our Lords and Masters who write the laws are idiots of course and that would never do would it? 

It also seems like an eminently sensible change:

Councillors in other local authorities have also complained that Uber drivers who do not fulfil the authority’s specific licensing requirements – such as minimum vehicle age and successful completion of a knowledge test for the area – can still operate legally in their jurisdiction with a licence from elsewhere.

Licensing fees also vary from area to area, leading some to suggest that drivers are seeking out the authorities where it is cheapest to get a private-hire licence.

Reading council denied Uber a licence to operate last year, but during the summer’s Reading festival an average of 1,000 passengers a day took a trip using the taxi app. Although it is not known where the drivers travel in from, it is thought that many are licensed by nearby Slough borough council and Windsor and Maidenhead borough council.

Sensible on several levels. With sat nav that local knowledge requirement is rather old fashioned. Monopolists do tend to be monopolists and there's always the possibility that licensing fees will become, given the former monopoly of their issuance, a nice little tax upon the taxi using public.

But perhaps most important a series of locally planned monopolies is going to have a capacity problem. Demand is hugely variable across small areas - look at that festival there. If provision is limited to the drivers the area would more normally support then many will not be able to get a cab at those times of high demand. Allowing the one license which can then be used nationally leads to supply being able to move across those local authority borders and thus match demand more closely.

The end result of this should be greater efficiency of use of the fleet (and drivers). Which is pretty much the economic offering from Uber in the first place, less time waiting for a ride (on either side, driver or passenger) and thus a more efficient use of said fleet. More rides from fewer cars and less driver time, an increase in economic efficiency and as always with one of those, something that makes us all richer.

We can't see what 's wrong with this picture at all and it's most certainly not a loophole, is it?