Reports suggest that doctors are establishing "death lists" of patients to be put on the Liverpool Care Pathway (LCP), which allows family members who have witnessed loved ones undergo a controversial end-of-life regime to share their experiences with health officials.
Articles also claim that hospitals might be employing the method to cut costs and save bed spaces.
But medics have argued that the pathway has "transformed" end-of-life care, saying it can offer peaceful, pain-free deaths when used properly.
The review is being led by Baroness Neuberger.
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Accompanied by the Duke of Edinburgh, the Queen will attend the opening ceremony of the fifth session in the Holyrood chamber.
Ms Leadsom has received the backing of Ian Duncan Smith, the former work and pensions secretary.
The former shadow work and pensions secretary is considered a more viable candidate than Angela Eagle, a Labour source has told ITV News.