Cuba has agreed to release 52 political prisoners, including five dissidents to be freed within hours Wednesday, after breakthrough talks led by Spanish Foreign Minister Miguel Angel Moratinos.

If the move goes ahead it would be the biggest prisoner release since President Raul Castro took over the reins of power from his brother Fidel in 2008.

The remaining 47 dissidents will be freed within the next three to four months by the island's Communist authorities, Roman Catholic church officials said in a statement.

The statement did not identify the political prisoners to be freed, nor did it mention high-profile dissident Guillermo Farinas, who is said to be near death from a months-long hunger strike.

But the news of the dissidents' imminent release came after Spain's top diplomat met with Cuban leaders in a bid to free the political prisoners and save Farinas's life.

Moratinos met in Havana with President Raul Castro, dissident leaders and top church officials to achieve the breakthrough.

The Cuban Human Rights and National Reconciliation Commission (CCDHRN) -- an outlawed but tolerated dissident group -- estimates there are 167 political prisoners in the Caribbean nation of more than 11 million people.

Agencies