A prominent Hungarian campaigner who attempted to change the law on euthanasia, and shifted public opinion in the process, has died aged 47.

Human rights lawyer Dr Dániel Karsai rose to public prominence after being diagnosed with amyotrophic lateral sclerosis (ALS), a fatal form of motor-neurone disease, in 2021 and launching his campaign.

He led cases in domestic and European courts in an attempt to legalise assisted dying, which is strongly opposed by the ruling centre-right party.

Helping someone to die at home or abroad carries a prison sentence of one to five years in Hungary.

Dr Karsai campaigned to legalise active euthanasia, in which a physician gives a patient a lethal drug. While he lost each case, he won significant popular support.

According to one survey by the Median agency, two thirds of the Hungarian public now support euthanasia despite opposition from the government and the church, and a tradition of social conservatism in the country.

Realising he would not be to able change the law in his own lifetime, Dr Karsai gave frequent updates on his condition and thoughts.

“Let me be clear… I don’t want to die today and I don’t want to die tomorrow”, he told an audience in Budapest in October 2023.

“But it is possible that I will be in a physical state where there is nothing but suffering.

“And when there is only suffering, then no one can philosophize any longer.”

Top government officials had expressed compassion for Dr Karsai.

“We stand with him, we sympathise with him, we wish him much strength”, Prime Minister Viktor Orban told reporters in December 2023, adding “and if he allows us, we will also pray for him”.

But Orban and his governing Fidesz party refused to change the law – something only they had the power to do due to their large parliamentary majority.

The Ministry of Justice insisted that the right to life, enshrined in the constitution of 2011, was inviolable.

In June 2024, the European Court of Human Rights – Mr Karsai’s former workplace – ruled in favour of the Hungarian government’s argument that the denial of euthanasia was not an infringement of his fundamental rights as a Hungarian citizen.

In September, the European Court of Justice also ruled against him.

Within hours of Dr Karsai’s death, the Hungarian Chamber of Physicians announced a memorial prize in his name “to support the aims of individuals and organisations fighting for dignity at the end of life”.

A play partly written by Dr Karsai, One Perfect Day, premiered in June in Budapest’s 6SZÍN theatre. A book of his Facebook posts and other writings and public remarks will be published in October, and a documentary film chronicling his last years will be released in 2025.

His support team and family are expected to continue his campaign.