A New Zealand woman who is dying of an inoperable brain tumour is taking her fight to be given the right to die when she wants to the High Court.

Wellington lawyer Lecretia Seales was diagnosed with terminal brain cancer in 2011 at the age of just 37.

Despite undergoing surgery and a range of drug therapies to try and keep the tumour at bay, recent MRI scans show it is advancing and doctors have told her she may only have months to live.

Armed with that knowledge, Ms Seales is asking the Court for a judgement that would ensure her GP won't face charges if and when she assists her to die.

"I am the one who has been inflicted with this disease, no one else. It is my life that has been cut short," says Ms Seales.

"So who else but me should have the authority to decide if and when the disease and its effects are so intolerable that I would prefer to die?"

Ms Seales says she understands the need to protect vulnerable people who could seek to end their lives but that it shouldn't be so difficult for her or any New Zealander to exercise their human rights.

"I am simply saying that I, Lecretia Seales, a human being confronted with the inescapable reality of my death, and the prospect of great suffering - for me and those who love me - must have the right to determine when I have reached the end of the road. This right belongs to me and none other."

Her case follows a decision by Canada's Supreme Court last month that found the country's ban on doctors participating in assisted dying infringed human rights.