By Ray Furlong
BBC Radio 4's PM programme
Tamil protester Mr Subramaniam began his hunger strike on 7 April
Huddled under blankets in the middle of London's Parliament Square, a lone Tamil protester is starving himself to death - and as he explains in a voice weakened by hunger, he is not afraid.
Protests in Parliament Square are not supposed to be allowed, but it has not stopped Tamils mounting a demonstration there for nearly three weeks.
They want the British government to intervene and push for an end to the civil war in Sri Lanka.
And in the middle of it, lying in a tarpaulin bivouac and unable to lift his head is 28-year-old Prarameswaran Subramaniam.
"I want freedom for my people," he explains, his voice weak and cracked. "And the price for that freedom? - my life."
Mr Subramaniam's resolution seems to come from living through years of conflict in Sri Lanka - and also from personal tragedy.
"My whole life I am suffering at the hands of the Sri Lankan government and army. In '87 my dad was killed by the Sri Lankan navy, and now 25 days ago my family were killed by poison gas, chemical weapons," he says.
"I was held for nearly two years in jail without any reason."
I interview Mr Subramaniam lying on my side, leaning on one arm and holding my microphone with the other.
I am near enough to hear him over the roar of London traffic, and also to see the fading light in his eyes.
He says he came to London two months ago, but will not explain under what circumstances for fear that those who helped him could be arrested, tortured and killed.
So did he plan to mount a hunger strike in London?
"I always wanted to do something for my people. If I take up arms the government will call me a terrorist, if I do a hunger strike in Sri Lanka they will just say I have saved them a bullet," he explains.
Mr Subramaniam is not the first Tamil hunger striker. In 1987 Amirthalingam Thileepan, a leading member of the Tamil Tigers - or Liberation Tigers of Tamil Eelam (LTTE) - starved himself to death.
And Mr Subramaniam, who says he is not an LTTE member, says others may follow.
"It's bad if people go on hunger strike after me, but I can't stop them," he says.
"Doing a hunger strike is hard, it's painful, but when no-one is listening to us we can't do anything else.
"Now you are here. Before, we did demonstrations and you didn't come and report our opinions. But now you are here - after I started the hunger strike."
I ask Mr Subramaniam whether he is afraid of dying.
He says: "No, no, no, I'm not worried - because I saw many thousands of deaths of friends of mine. That means livers, kidneys and stomachs coming out, people dying, right in front of my eyes.
"When I was in Sri Lanka I was always close to death, every day."
Still, at 28 years old, he is a young man.
"But others, younger, are also dying: even children in their mother's stomachs. No-one can imagine these things," he says.
When we finish speaking he closes his eyes and seems to fall asleep. The crowd of Tamil protesters are chanting demands for a ceasefire - also one of Mr Subramaniam's conditions for ending his hunger strike.
But the Sri Lankan government has resisted these calls, arguing that they would merely allow the LTTE to regroup.
It accuses the LTTE, which the British government also regards as a terrorist organisation, of causing civilian casualties by holding people as human shields.
The LTTE is fighting for a separatist state in the north and east of the island.
As Mr Subramaniam lies with his eyes shut, the chants go on, the police stand watch, and black cabs and open-top tourist buses pass by. And in Sri Lanka the fighting continues.