Thousands of pilgrims swarmed into central Rome on a drizzly Saturday amid tight security measures on the eve of a ceremony for late pope John Paul II’s beatification, a critical step towards sainthood.

“I couldn’t miss this, I had to be a part of such a historic moment. We’ve only just arrived but the atmosphere’s great, it’s really exciting,” said Patricia Wocial, 48, who had come from Britain with her young daughters.

The weekend of prayer, which experts say could help the Vatican burnish an image badly tarnished by paedophile priest scandals, will kick off later today with a vigil in the ancient Roman arena Circus Maximus. Some 500,000 pilgrims are expected for the beatification, which will confer the status of “blessed” on the pope, who survived an assassination attempt and helped fight Communist rule during his nearly 27 years in office.

John Paul became pope in 1978 — the first non-Italian pope in more than four centuries. After 104 foreign trips and a pontificate that gave new strength to the Catholic Church, he died in 2005 following years of ill health.

The late pope’s coffin has been brought out of its resting place in a crypt under Saint Peter’s basilica, and a phial of John Paul’s blood, drawn from him during his illness, has been prepared as a relic for veneration.

At least 100,000 people are expected to attend the vigil starting at 1800 GMT today to hear those who were close to John Paul II speak, including his former personal secretary, Cardinal Stanislaw Dziwisz.

Among the speakers will be Marie Simon-Pierre, the French nun whose miraculous healing from Parkinson’s disease is the official justification for John Paul II’s beatification after years of research by the Vatican.

While some pilgrims will then head off to bed before Sunday’s beatification mass starting at 0800 GMT, others will take advantage of several churches in central Rome which are staying open all night to pray to the late pope.

“We’re planning to camp out at the vigil until midnight, then go from church to church to pray, before heading to the Vatican around 4:00 am (0200 GMT) to soak up the atmosphere and get the best seats possible,” Wocial said.

Peddlers could be seen hawking tacky souvenirs including watches with the pope’s face and baseball hats and T-shirts reading “I Love JPII”. Scout groups could be seen in Saint Peter’s on Saturday waving yellow-and-white Vatican flags, while other pilgrims sang religious songs.