We need double the doctors we have, which means training more, persuading all qualified ones who have quit back into the NHS, and welcoming ones from overseas with messaging as well as it being legally possible to get visas.
I agree with all of this, @LadyCordeliaVorkosigan, and think they could do more to encourage young people into medicine.
I'd be happy for doctors' (and nurses') student loans to be written off after spending 10 years working solely in the NHS. Doctors' tuition fees alone must be shedloads, as it's over 5 years instead of the normal 3. They can't work p/time while training as they have to work on the wards, so can't commit to other work.