Changing the law to legalise assisted dying could see people killed because they are old, an at-times emotional parliamentary debate has heard, while others rejected a picture painted of a country “teeming with granny killers”.

Westminster Hall was packed for a debate on Monday afternoon which saw MPs give impassioned speeches for and against legislative change.

Dame Esther Rantzen was praised for her role in bringing the conversation to the fore, having revealed in December that she has joined the Swiss Dignitas clinic as she lives with stage four cancer.

It is the campaign that has most touched a nerve with people throughout the broadcaster’s long career, the debate heard.

A petition backed by Dame Esther as part of a Daily Express campaign gained more than 200,000 signatures to see the topic again debated at Parliament.

Opening the Westminster Hall debate, Labour MP Tonia Antoniazzi, a member of the Petitions Committee, said public opinion on assisted dying “has shifted in one direction”, citing polls by Dignity in Dying showing “overwhelming support for law changes with safeguards in place” and a rise in UK members of Dignitas.

The issue was last voted on in the Commons in 2015, when it was defeated at second reading by 330 votes to 118.

Monday’s debate had no vote, but was a chance for MPs to share their own and their constituents’ views on the issue.

Conservative MP Siobhan Baillie began to cry as she shared the testimony of a man who had written to her about his mother’s death.

She said the man’s mother had “considered taking her own life as her best friend had actually done”, but did not, despite being deeply unwell, and had then taken 16 weeks to die “effectively from starvation”.

Conservative former minister Sir Desmond Swayne likened the situation to 1970s science fiction film Logan’s Run, saying a law change could lead to people being killed simply because they are old.

He told the debate: “There is a profound danger in my view that what begins as a choice will end as an expectation, and so proceeding you will end up with Matthew Parris, and then it is not much of a jump until you are at Logan’s Run. Don’t know what it is? Google it.”

Get off the fence, don’t sit on your hands, have a proper, full debate about all the implications, and at the end of that I am sure they will introduce legislation

His party colleague Therese Coffey also spoke out against a change, telling MPs: “No-one should feel such a burden on their family, their friends and society that they should end their lives early.”

But fellow Tory Kit Malthouse rejected a view he said was being presented of a country “teeming with granny killers, all of us waiting just to bump off a wealthy relative so we can pocket the cash, like we’re some kind of nation of Jeremy Bambers, intent on remunerating ourselves”.

He insisted “the vast majority of the British people, they love their parents, they love their grandparents, they want the best for them” and said any new law should have safeguards.

He also warned there is the “business class” option where someone who has the money “can have what the law denies to everybody else”, branding it “an outrage”.

Labour MP Paul Blomfield suggested the current law is “unsafe, and assisted dying laws are safer than blanket bans”.

Noting the interest in people having their say, Conservative former minister Tobias Ellwood remarked on the “packed” room, saying extra seating had been brought in.

Instead of discussing this dangerous and ideological policy, we should be talking about how to fix the UK’s broken and patchy palliative care system so everyone can have a dignified death

“I wager that there are more colleagues here than there are in the main chamber,” he said.

Urging caution, Labour MP Rachael Maskell said her concern lies with someone who feels they are “just getting in the way” and thinks that “my children themselves will have a better future without me”.

She said it is not “necessarily coercion” but rather “the way that people feel in a society that changes the law”.

Responding to the debate on behalf of the Government, justice minister Laura Farris urged MPs to remember some vulnerable people do not have loving families and may be subject to coercion in regard to assisted dying.

Acknowledging arguments from some parliamentarians that most people with terminal illnesses have close families who would not seek to harm them, she said: “Implicit in that is that a minority don’t, and are in dysfunctional families, and may not have loved ones.

“We must consider the consequences or the potential risks for them too.”

While it has been suggested by both Labour leader Sir Keir Starmer and the current Government that any potential law change could come through a private member’s Bill, this was said by some to be “the wrong mechanism”, with a number of MPs arguing more time would be needed to scrutinise any new legislation.

Demonstrators on both sides of the debate had gathered outside Parliament ahead of the argument, with broadcaster Jonathan Dimbleby among them.

In an interview with the PA news agency, he said politicians must “get off the fence” and commit to a “proper, full debate”.

He has previously described the current law as “increasingly unbearable” after the death of his younger brother Nicholas, who suffered with motor neurone disease (MND).

In a message to MPs, he told PA: “Get off the fence, don’t sit on your hands, have a proper full debate about all the implications, and at the end of that I am sure they will introduce legislation.”

He described the Not Dead Yet protest being held next to the Dignity in Dying demonstration as impassioned but unreasonable, saying some of the slogans were “scare stories that I wish that people wouldn’t deploy because of their own very strong feelings”.

Those who oppose a change in the law have voiced concerns that legalising assisted dying could put pressure on vulnerable people to end their lives for fear of being a burden on others and argue the disabled, elderly, sick or depressed could be especially at risk.

Dr Gordon Macdonald, chief executive of the campaign group Care Not Killing, described Monday’s debate as a missed opportunity to talk about fixing the UK’s palliative and social care system.

He said: “Instead of discussing this dangerous and ideological policy, we should be talking about how to fix the UK’s broken and patchy palliative care system so everyone can have a dignified death.”

Assisted suicide is banned in England, Wales and Northern Ireland, with a maximum prison sentence of 14 years.

In Scotland, it is not a specific criminal offence but assisting the death of someone can leave a person open to being charged with murder or other offences.

A Bill was introduced in Scotland in March – the third time members of the Scottish Parliament will have considered the issue.

Before the debate, the Government had responded to a health and social care committee report published in February, saying it will discuss with the devolved administrations and crown dependencies “the practical implications for England and Wales” of legislation in nearby jurisdictions “and any constitutional issues that such legislation may present”.