Mourners who cried "santo subito" ("saint immediately") at the funeral of Pope John Paul II are likely to have their wish fulfilled, after Pope Francis cleared his long-reigning Polish predecessor for canonisation with record speed.

Just eight years after his death and little more than two since his beatification, John Paul will be made a saint following the pope's approval of a second miracle attributed to his intercession.

The Vatican said the Argentinian pontiff had decided that the late Pope John XXIII, who opened the landmark Second Vatican Council in 1962, should also be canonised, despite no second miracle having been approved in his case.

The ceremonies are expected to take place by the end of the year. John Paul's could be on 22 October, his feast day and the anniversary of the liturgical inauguration of his 27-year-long papacy in 1978. But 8 December – the feast of the immaculate conception – has also been suggested as a fitting date. The rapid process by which Karol Wojtyła has been propelled towards sainthood will be welcomed by many of the world's 1.2 billion Roman Catholics, who regard him as a towering figure who hastened the collapse of communism, encouraged interfaith dialogue and brought charisma to the church.

But it is likely to be met with anger among his critics, including those who cite his record in handling the clerical sex abuse scandal. Some believe he should never be made a saint, let alone less than a decade after his death.

When his successor, Benedict XVI, began John Paul's beatification process in May 2005, the month after he died, the Vatican said the usual five-year waiting period was to be waived because of "exceptional circumstances".

In 2011, after a first miracle had been attributed to John Paul, he was beatified by Pope Benedict in a ceremony attended by several hundred thousand people in St Peter's Square and the surrounding streets.

According to t he Vatican, that first miracle concerned the inexplicable recovery of a French nun, Sister Marie Simon-Pierre Normand, who was apparently dying of Parkinson's disease but was cured after she and her fellow nuns prayed for the intercession of the late pope. He himself died of the disease in April 2005.

For John Paul's canonisation to take place a second recovery deemed by the Vatican to be a miracle has also been approved. On Friday the Catholic Church in Costa Rica presented 50-year-old Floribeth Mora and her doctor to reporters.

With tears in her eyes, Mora described how she was diagnosed with a brain aneurysm in 2011 and sent home with pain medicine but no apparent hope for treatment, thinking she was going to die.

She said a photograph of the pope seemed to speak to her during the deceased pontiff's beatification, and her doctor Alejandro Vargas said the aneurysm disappeared for no apparent reason.

The highly unusual decision by Francis to canonise John XXIII, who reigned from 1958 to 1963, without a second miracle will raise eyebrows.

Observers suggested the current pope – who has made the common touch the trademark of his fledgling papacy – felt an affinity with the Italian known to many Catholics as "Good Pope John". Like Francis, he enjoyed making pastoral visits, visiting children in hospital and inmates in prison.

And, like Francis, he also valued spontaneity and the freedom to liberally interpret security arrangements, taking late-night strolls around Rome.