Margo MacDonald needs the support of 18 MSPs to take it before parliament
The MSP behind plans to legalise assisted suicide hopes to bring legislation on the issue to the Scottish Parliament by the autumn.
Margo MacDonald's comments came as she revealed about 400 people and groups on both sides of the debate responded to a consultation on her proposals.
The independent Lothian MSP is still short of the 18 MSPs needed to have a bill considered by Holyrood.
Ms MacDonald said she was confident of making up the numbers.
The MSP, who suffers from Parkinson's disease, has expressed her own wish to choose a dignified death.
Ms MacDonald, 65, has also won the backing of Edward Turner, whose mother, Dr Anne Turner, chose to end her own life in a Swiss clinic while suffering from the degenerative neurological condition, progressive supranuclear palsy.
Ms MacDonald is also using the consultation responses - which are currently being analysed - to clarify the measures contained in the proposed End of Life Choices Bill.
"There are people who will be undecided about their eventual opinion on physician-assisted suicide, assisted dying, choices at the end of life - call it what you like," said Ms MacDonald.
"They're not quite certain yet, but they do recognise there is a wish in public opinion surveys for the proposal to become a firm recommendation in the contents of a bill."
Dr Turner was recently portrayed by Julie Walters, in a TV dramatisation of her story.
Speaking at Holyrood, her son said: "When people go to somewhere like Switzerland, they are forced to go before their time.
"My own mother was terrified of losing the ability to travel and she went at a relatively early stage in her condition.
"If assisted dying had been legal in the UK, then she would have had extra months of life."
Ms MacDonald's legislation, which has been supported by at least 12 MSPs, would incorporate the patient's right to choose to end his or her life, with assistance from a physician.
People would need to be registered with a doctor for "a considerable period of time" before they could request help to die and would have to make two requests for such help, at least 15 days apart.
Meanwhile, Scottish Labour leader Iain Gray has called on the Scottish Government to boost the number of specialist nurses who deal with Parkinson's sufferers.
He claimed there were only about 25 such nurses, while about 10,000 people had the illness.