ARPUTHAM AMMAL, a pensioner with curly silver hair and a wheezing cough, is an abolitionist. Perched in a gloomy warehouse in Chennai, capital of Tamil Nadu, as young men bustle over an exhibition against the death penalty, she explains why. “It is not needed. The ultimate victims of the death sentence are the backward, the minorities and the weak.”

She has another reason for her opposition: in a few weeks a hangman is due to slip a noose around her son's neck. Known as Perarivalan, he was convicted with 25 others of killing Rajiv Gandhi in 1991. Judges ruled that he supplied a battery for the suicide bomber who blew up the former prime minister. Yet for over a decade he has languished in jail awaiting a response to his plea for mercy. In August President Pratibha Patil rejected the plea, and those of two co-conspirators.

The three were to be hanged on September 9th. But a local court issued a further stay, ironically to decide if the years of delay, largely in solitary confinement, were a cause for commutation. Delays are universal in India; 16 similar pleas are now before the president. Of 300 people on death row, many have waited for years. The lawyer for an Assamese murderer says of these repeated, last-minute postponements: “You are virtually killing him every day.”

India has imposed a near-moratorium on capital punishment since the Supreme Court ordered in 1983 that it be used only for the “rarest of rare” cases. Only one convict has been hanged since 1995. (The neighbours, too, have grown shy of the noose, resulting in crowded death rows: 357 await execution in Sri Lanka, 400 in Bangladesh and some 8,000 in Pakistan.) The news that Gandhi's assassins would hang spread consternation, especially in Tamil Nadu where resentment of the distant, northern rulers in Delhi is palpable.

Locals grumble that India does nothing for their fellow Tamils in nearby Sri Lanka, who are seen as victims of an ethnic assault by the Sinhalese-run government. Now Tamils have another cause. On August 28th a woman in Tamil Nadu burned herself to death to protest against the imminent hangings. The state assembly also voted unanimously against them. Activists talk of spreading opposition. A prominent politician, Vaiko, roars in his office that the hangings would be a “betrayal of the Tamils”, and would provoke popular fury.

Few doubt that the three now facing execution were involved at a lowish level in Rajiv Gandhi's murder. But serious questions persist over the investigation and trial, carried out under a now-defunct anti-terrorist law. The convictions rested on confessions, later retracted, that were beaten out of the suspects by the police.

A retired police inspector, Mohan Raj, also wants the hangings called off. He says ruefully that he would testify that he assaulted the condemned to make them talk. Mrs Ammal's son, Perarivalan, was “beaten blue-black” he admits. “What do you expect? The country's leader was blown faceless. We were all very furious against these fellows.” The convicts call this torture. Perarivalan, who was 19 at the time, has written of how Mr Raj and others attacked him with plastic pipes filled with concrete, kicked and punched him, denied him sleep and water, put him in agonising positions and stuck pins into his fingernails until he signed statements of guilt.

With such abuses widespread in Indian custody, retired judges and others are now campaigning for outright abolition of the death penalty. The risk of hanging an innocent person is too great, they say. At the same time, the rarity of execution means it is no deterrent. K.T. Thomas, who presided over the Supreme Court that upheld the death penalty in the Gandhi case, now calls its use “inhuman” and merely “vengeful”.

Yet the ruling Congress party may conclude otherwise. Taking the death penalty off the books might encourage more police to serve as illegal executioners, in a practice known as staging “fake encounters”: shooting suspects dead and claiming afterwards there had been a firefight. Hanging may be unpopular abroad, or blocked by courts or regional politicians sensitive to local feelings. But it can still secure a populist boost from voters, especially those angered by official failures to prevent terrorist attacks. A big test will be the fate of a Pakistani prisoner, Ajmal Kasab, who is the sole surviving attacker from the November 2008 assault on Mumbai that killed some 170. Last year he was sentenced to death four times over. It will be a brave Indian who demands that he be spared.