The comments from Thea Stein, chief executive of the Nuffield Trust, came after MPs voted 330 to 275 in favour of the legislation on Friday.

Stein said: ‘As this Bill progresses through Parliament, MPs will need to carefully consider how such a change in the law would interact with the NHS and social care. There are large unanswered questions around funding, staffing and equity if this Bill becomes law.'

The think-tank chief executive said it was ‘still unclear' whether the legislation would be publicly funded, adding implications for people paying for social care would need to be addressed, as well as how to fund the policy from an ‘overstretched' health budget.

Stein said questions remained around who will be expected to provide the service, whether it will be carried out privately or as part of the NHS and how it will be regulated, as well as what changes to staff training and education will be required.

She added: ‘Our work reveals that care at the end of people's lives is not always equal and often does not give people the choices they want. Meanwhile, specialised palliative care misses out many who could benefit from it. This Bill must focus minds on how to ensure better provision of both palliative and end-of-life care so that people opting for assisted dying are doing so in the context of a fairer and more equitable service than we have today.'

The Nuffield Trust is neutral regarding legislation of assisted dying.