Viva la revolucion? Cuba fifty years on

When optimists talk of the changes taking place across Cuba now that the great helmsman of the revolution Fidel Castro has been parked in a retirement home to be replaced by his 77-year-old brother Raul, I think back to my friend Carlos and his family.

They live a few hundred yards from the historic downtown area of Havana where pedestrians stroll at all hours and the streets are thronged with cultural tourists from Europe as well as those who have come for the cheap sex. To reach the tiny flat, I have first to check that no one is following before ducking through a doorway to a dank courtyard. Then it's up an ancient flight of stairs, open to the elements, to reach his home.

Care is needed because the Specialised Police are everywhere in Havana. They seem to have two functions. The first is to ensure that nothing disturbs the flow of tourist dollars to government-owned hotels. The second is to ensure that ordinary Cubans are kept as far as possible from the visitors who might give them ideas about human rights.

Carlos's floor is divided between four families with a linking passageway outside. There is almost no privacy and he and his family are cooped up like battery hens in the tumbledown building. It seems not to have had a lick of paint since the revolution. And because Carlos is himself a human-rights activist he has never been able to find work. By inviting me into his home without official permission, which would never be granted, he risks being arrested.

But sitting in the family's tiny kitchen, he enthusiastically digs out bundles of photographs he has taken of the "Damas de Blanco" (literally: "The Ladies in White"). It's an opposition movement of the spouses of 80 Cuban dissidents who were rounded up in 2003 and sentenced to long terms in squalid jails. They were charged with accepting money from the US and with hijacking and terrorist activities. Among them were trades unionists and academics, and within two weeks of the arrests their spouses began marching to church dressed completely in white.

They gather before mass and march together to St Rita's Catholic Church in Havana. Even the parish priest dislikes them because of the way they threaten the church's cosy relationship with the Communist government. Cuban exiles hate them, too, because the last thing the dissidents want to see coming to Cuba is American-style capitalism.

Although the movement received the Sakharov Prize for Freedom from the European Parliament in 2005, they are left mostly alone in their struggle, living on handouts from the movement while their spouses rot in prison. Cubans who stick their necks out to criticise the regime quickly see its thuggish side. But Carlos is a resourceful man and he has so far avoided the clutches of the secret police.

But consider the case of Oscar Espinosa Chepe, a 67-year-old who lives on the other side of town. A diplomat and a brilliant economist, he had the temerity to tell the politburo that things weren't functioning as they should. When the Berlin Wall came down in 1989, he assumed the same thing would happen in Cuba and began agitating for change.

Castro was having none of it and Oscar was thrown in jail, where he became chronically ill. His wife, Miriam, lobbied for his release and eventually with European pressure he was allowed home, where the threat of re-arrest still hangs over him. But Oscar is delightful company – all the more so because of his encyclopedic knowledge of Cuba's economy.

He opens the refrigerator and proceeds to give me a lesson in economics from the pitiful items he has received from the rationing system, which has been feeding Cubans since 1962 when the US embargo went into effect. It's all detailed in a "Libreta de Abastecimiento" (or "Supplies Booklet") that covers everything from cigarettes and matches to cooking oil. It even includes a supply of charcoal for cooking with.

Rationing is part of the Castro brothers' tyranny and – along with neighbourhood spies – the Libreta is a useful device for maintaining social control. The Libreta has a page per month, where the quantities of products bought at subsidised prices is marked. And, of course, no Libreta means no food.

Oscar hoots with laughter at the incompetence of the regime and points to the ceiling, where he indicates that all his conversations are being listened-in to, by a rotating squad of secret policemen who occupy the flat above. Miriam, his wife, is a member of the Damas de Blanca, and chips in to describe how almost nobody bothers to attend the compulsory meetings called by local Committees for the Defense of the Revolution.

"The woman comes by every week, shouting at us to attend, but nobody bothers," Miriam says. "The woman hollers: 'En cada barrio, Revolucion!' ["Revolution in every neighbourhood!"] But everyone knows it's a sham."

If there is one thing that brightens Oscar's day, it is the imminent arrival of Barack Obama – a man he hugely admires – in the White House. But he is realistic enough to realise that the gang who run Cuba are not going to change overnight.

Raul Castro, who was in charge of political executions at the start of the revolution, still likes to crack the whip. He recently told a meeting of party officials, "When the difficulties are great, the greater the need for order and discipline."

As it is for despots everywhere, the great fear of the Castros is that they and their cronies will be swept away in a counter-revolution and end their days in one of the dank prisons in which their political rivals have been incarcerated.

Under Raul, the government has finally admitted the scale of its problems – and this year Cubans have been allowed to buy previously forbidden goods including DVD players and mobile phones. They are also allowed to go into hotels – something they had been banned from doing – and there is even a new terrestrial television station broadcasting reruns of The Sopranos and other US dramas.

But wages are abysmally low, and under Cuba's complicated internal exchange rate hotels and restaurants charge in "convertible pesos" whose value is tied to the dollar. But this is a country where the average wage is 430 pesos a month – and those 430 regular pesos are worth only about 17 convertible pesos.

So only the politically connected, the corrupt or those getting money from family in America can afford to buy consumer goods. And having a mobile is one thing, but the charges are among the highest in the world at US$1 a minute.

And that is why so many Cubans work the black market – with even government ministers getting in on the action. Now Cuba faces another crisis with the collapse in the price of nickel, its most valuable export. So even the glacial pace of change brought in by Raul is slowing again.

Back in his flat, my friend Carlos is putting away his photographs as he spits out his contempt for the rulers of his country. As I leave, I see pairs of eyes follow me down the narrow stairs. I worry for the safety of my friend and ask if my visit will bring unnecessary danger.

Setting his jaw defiantly, Carlos tells me that without the basic freedom to speak his mind, there is nothing left to lose.