Outside parliament in London, rival protesters rallied as lawmakers debated a bill to allow terminally ill patients to end their lives that has sparked fierce opposition from religious leaders.
It was the first time in 20 years that British MPs have discussed the controversial issue, although the backbencher-proposed bill itself is not expected to become law and is opposed by Prime Minister David Cameron.
Around 200 campaigners came out in favor of the bill and there were dozens of protesters against it.
"82 Percent of Britons Support Assisted Dying and the Current Law is Broken: Fix It!" read placards held up by supporters, while opponents' signs read: "Do No Harm. Vote No" and "Assist Us to Live, Not Die".
Anglican leader Justin Welby, the Archbishop of Canterbury, and the heads of all of Britain's main faith groups wrote a joint letter to MPs last week urging them to throw out the assisted dying bill.
"While it is not a crime in the UK for someone to take his or her own life, we recognise that it is a tragedy and we, rightly, do all that we can to prevent suicide."
"The assisted dying bill requires us to turn this stance on its head, not merely legitimizing suicide, but actively supporting it," they said.
Under the plans being considered, two doctors and a family court judge would have to assess the patient's prognosis and confirm they were mentally competent and made the decision free from coercion. The patient would still have to administer the lethal medication themselves.
"At present, the law denies dying people the choice of a safe, legal assisted death, whilst turning a blind eye to home suicides, and to technically illegal actions by doctors, and to Dignitas deaths," said Rob Marris, the MP from the main opposition Labour party who is proposing the legislation.
"As an MP, as a lawyer, and as an individual, I am convinced that we can and should allow better choice for dying people."
Friday's vote is only a first step if the bill were to become law, and it faces a daunting passage through the House of Commons and House of Lords if it is to get over the initial hurdle.
MPs are free to vote according to their conscience and the parties are not imposing a whip or party line for voting, as would usually be the case.
Assisted suicide is legal in Switzerland, the Netherlands, Belgium and Luxembourg as well as in the US states of Vermont, Oregon and Washington.