Uber, Deliveroo, Hermes and Amazon have thousands of people working for them, many full-time, most who don't have the rights and protections that other full time staff enjoy.

Sick pay, holiday pay, the guarantee of the National Living Wage - that sort of thing.

This morning the UK head of Deliveroo, Dan Warne, told the Work and Pensions Committee MPs the company is willing to pay all of its riders greater benefits but the law prevents them.

"We're restricted from providing some benefits that we as a business would like to provide" Dan Warne told MPs, indicating a willingness for Deliveroo to make pension contributions, for example if the government legislates.

The company seems keen to be more generous but wants to ensure that its riders remain self-employed.

The government is looking at this issue. Mathew Taylor is leading an inquiry into self-employment Britain and the implications for both workers and the taxpayer.

Meanwhile the unions are in the process of taking legal action and direct action.

Taxi cab drivers stage an anti-Uber protest. Credit: ITV News

This morning a group of taxi drivers gate-crashed the Uber stand at The Business Travel show in London and chanted slogans like "corporate travellers shouldn't lose slave labour!"

Last October an employment tribunal in London established they are "workers" and have some employment rights. Uber is appealing.

But CEO of Hermes UK raised a potential dilemma. Carole Woodhead told MPs that if Hermes is forced to employ all the people that currently work for the company as a contract then several thousand jobs will vanish.

"We would substantially change the nature of the operating model so instead of having 15,000 couriers it might be more like 6,000 full-time drivers" she said.

Uber, Deliveroo, Hermes and Amazon have been very successful in recent years. They've variously developed and harnessed technology in a way that enabled them to improve the services they offer, they've also stretched employment law to limit.

The Taylor inquiry and then the government will have to decide to either change the law or force the companies to change the way they do business.