There needs to be an actual ability to negotiate. If they say no, so be it, but Uber does not provide a mechanism for drivers to give a counter-offer, so there is no negotiation.
For your comparison to contracting, I've contracted quite a lot, and I have always had the ability to state my rate, and the client have had the ability to state theirs, and we arrive at something that may be mine, or theirs or something in between, but there has always been actual discussion.
With Uber you're presented with a price, and you take it or leave it, and if you leave it Uber never comes back with a higher price - on the contrary, if you keep leaving it they may penalise you.
That alone would not necessarily have caused it to be deemed employment, but combined with the other element that all points to drivers having very little control demonstrates that this is not a contract entered into by equals, but one were drivers are subservient, and that points very strongly to an employee relationship under UK law.
That there may be similar elements in your IT contracting does not mean Uber drivers are not employees, but that you might be.
E.g. when I did contracting:
* I always negotiated a rate, whether or not there was a middleman in the process.
* There was always a defined end to the contract (but it could be extended)
* I had marketing costs.
* I paid for my own equipment, and the costs were amortised over my contracts.
* I had more than one client at a time a lot of the time, but certainly more than one per year.
* I decided when I worked, and how to do the work, and where to work and it was not ordinarily in their offices.
Each one of those pointed towards me being a genuine contractor outside of IR35. Each one of them going the other way would not individually mean I was suddenly inside IR35 or in a deemed employment, but each additional one would increase the likelihood the relationship is an employment relationship.
EDIT: To make it clear, IR35 is the tax treatment only, but it's often a useful proxy to indicate whether or not you have a claim to be an employee, because the tests that indicate if you're within IR35 are much the same things a court or tribunal would consider if you were to ask them to rule on whether or not you're an employee.
EDIT2: Also, if you're a contractor in the UK but not resident that points to a short term contract. That does suggest you'd not be considered an employee, certainly.
For your comparison to contracting, I've contracted quite a lot, and I have always had the ability to state my rate, and the client have had the ability to state theirs, and we arrive at something that may be mine, or theirs or something in between, but there has always been actual discussion.
With Uber you're presented with a price, and you take it or leave it, and if you leave it Uber never comes back with a higher price - on the contrary, if you keep leaving it they may penalise you.
That alone would not necessarily have caused it to be deemed employment, but combined with the other element that all points to drivers having very little control demonstrates that this is not a contract entered into by equals, but one were drivers are subservient, and that points very strongly to an employee relationship under UK law.
That there may be similar elements in your IT contracting does not mean Uber drivers are not employees, but that you might be.
E.g. when I did contracting:
* I always negotiated a rate, whether or not there was a middleman in the process.
* There was always a defined end to the contract (but it could be extended)
* I had marketing costs.
* I paid for my own equipment, and the costs were amortised over my contracts.
* I had more than one client at a time a lot of the time, but certainly more than one per year.
* I decided when I worked, and how to do the work, and where to work and it was not ordinarily in their offices.
Each one of those pointed towards me being a genuine contractor outside of IR35. Each one of them going the other way would not individually mean I was suddenly inside IR35 or in a deemed employment, but each additional one would increase the likelihood the relationship is an employment relationship.
EDIT: To make it clear, IR35 is the tax treatment only, but it's often a useful proxy to indicate whether or not you have a claim to be an employee, because the tests that indicate if you're within IR35 are much the same things a court or tribunal would consider if you were to ask them to rule on whether or not you're an employee.
EDIT2: Also, if you're a contractor in the UK but not resident that points to a short term contract. That does suggest you'd not be considered an employee, certainly.