The idea is that whichever law allows companies to send people to private doctors, who are obviously working in the interests of the company, not the patients (in breach of some of the most basic tenants of their profession) needs to be changed in some manner so that these unethical sellout doctors cannot overrule your own GP.
Your own GP acts in the interests of a patients wellbeing, as it should be, whereas an unethical private doctor working only in the interests of a company only has their own financial interests and the interests of the company they have sold out to in their minds.
Why is this idea important?
The idea is important as health is more important than a doctor unethically selling out the basic principles of their profession to the highest bidder in order to help a company stop people taking time off work if necessary to save the company money.
The basic tenants of the medical profession should be a patients wellbeing, not a companies wellbeing, and making a patient's health worsen.