Dame Esther Rantzen has urged MPs to attend the assisted dying debate, saying it is unlikely the issue will come before Parliament again in the next decade.

The broadcaster, who is terminally ill, has been a strong advocate for changing the law to allow dying adults to take their own lives in limited circumstances, without fear of their families being prosecuted for helping them.

She has written to MPs ahead of the debate on Friday, after which it is expected a vote will take place on whether to send the proposed legislation to a committee for further scrutiny.

The 84-year-old revealed in December last year that she had joined Dignitas, to give her the choice of an assisted death in Switzerland.

She said no matter which way MPs feel on the controversial issue of assisted dying, they should attend the debate and listen to both sides and make a decision because “every vote will be crucial”.

This will probably not come before Parliament as an issue to debate for another decade. How many more will be forced to suffer until then?

In a letter in conjunction with pro-change campaign group Dignity in Dying, Dame Esther wrote: “Please forgive me contacting you to ask you to attend the debate on Kim Leadbeater’s Bill on Friday November 29th, and please vote.”

She described it as a “vital life-and-death issue” and one “we the public care desperately about”.

She added: “So it is only right that as many MPs as possible listen to the arguments for and against, and make up your own minds, according to your own conscience, your personal thoughts and feelings.”

She pleaded with MPs to attend and vote, “whether you agree with my decision or not”.

She added: “This will probably not come before Parliament as an issue to debate for another decade. How many more will be forced to suffer until then?”

Dame Esther has previously stated that while not well enough to be there in person, she will “certainly be glued to my television with my fingers firmly crossed that the vote will go the way the vast majority of the public want, and have waited for for so long”.

In her letter on Wednesday, she acknowledged that any new legislation will “never apply to me as I have stage four lung cancer, and my time is running out”.

She described herself as “fortunate” to have the choice of an assisted death at Dignitas, but repeated her views that to have to go alone for fear of her family being prosecuted is unfair.

She said: “My family cannot accompany me there and support me, otherwise they will be investigated by the police for possibly assisting suicide which could mean a prison sentence of 14 years under the current law.

“Is that really the way our legal system should treat patients and their families at the most distressing time in our lives?”

Dame Esther noted that some people are opposed to the Terminally Ill Adults (End of Life) Bill – which covers England and Wales only – based on their religious faith, but added: “Although some seem reluctant to declare that is the reason for their opposition to the Bill.

“But I respect their decision.”

It’s not a choice between better palliative care and assisted dying. We all want the best possible palliative care. Terminally-ill people in the last six months of life are already being treated

Some people opposed to the proposals have raised concerns about palliative care and how that might be affected, or called for more focus on improving care instead of legislating for assisted death.

But Dame Esther said: “It’s not a choice between better palliative care and assisted dying.

“We all want the best possible palliative care. Terminally-ill people in the last six months of life are already being treated.”

She said the “tragic truth” is that, no matter how good the palliative care is, “it cannot prevent some kinds of suffering”.

Estimates published earlier this week suggested that more than 7,000 people a year – or roughly 20 per day – in the UK are in pain in the last three months of their life.

The Office of Health Economics (OHE), which said it has no stance either way on the topic of assisted dying, said its estimates presumed the person was getting the highest standard of care available, likely to be in a hospice.

This means the true number of people dying in pain is “likely to be significantly higher than our conservative estimate”, the organisation said.