Getty ImagesThe number of people choosing an assisted death could top 4,000 a year within a decade of the law coming into force if MPs vote for it, a review of the policy says.
The estimate forms part of the official impact assessment, which has been carried out by civil servants to inform MPs as they debate whether to allow assisted dying in England and Wales.
It said initially the numbers coming forward would be low, but are expected to grow over time.
But even within 10 years of the assumed October 2029 start date, the upper estimate of just over 4,500 assisted deaths a year would represent less than 1% of all deaths, the document said. The lower estimate was just over 1,000 deaths.
The impact assessment also provides a financial analysis of the costs and savings involved – it is not a document that gets into the ethical or philosophical arguments for and against the policy.
It comes as the bill returns to the House of Commons later this month, with a crucial vote that will determine whether the bill becomes law expected to happen in mid June.
In the first six months, savings for the NHS could range from around £919,00 to £10.3m.
This figure includes hospital care, primary and community care, hospice, medicines and other care costs that someone choosing an assisted death would not need.
By the time the system has been running for ten years, savings could range from £5.84m to £59.6m.
But there will be costs too. Staffing an assisted dying service could cost in excess of £10m a year within a decade. And training costs in the first six months alone could be over £11m.
One assisted death would likely involve six health and care professionals working 32 hours.
It said this could take staff away from existing services, but the overall impact of this was uncertain.
And each panel that would review cases, comprising of a lawyer, psychiatrist and social worker, could cost £2,000 a day.
Overall, it said it was not possible to calculate whether the costs outweighed the savings or vice versa as there were too many uncertainties.
The Department of Health and Social Care said the government was neutral on the issue. It said the document had been produce to help ensure any legislation that passes through parliament is "workable, effective and enforceable".
Kim Leadbeater, the Labour MP behind the bill, said she was grateful for the work that had been done on the impact assessment.
She said she was still "firmly of the view that the overall impact of this long overdue reform will be to make end of life care in England and Wales more compassionate and significantly safer".
But Baroness Tammi Grey-Thomson, a former Paralympian and member of the House of Lords, who opposes assisted dying, said: "This assessment highlights how assisted dying would put disabled and other vulnerable people at grave risk by providing financial incentives to an already overburdened and under-resourced NHS to offer assisted dying as a 'treatment option'."
