The judging is strict and the marchers hope that their relentless rehearsing has paid off.

A regular winner is the Lisboa district of Alfama, famous as the birthplace of fado – the traditional melancholic song of Portugal. We move through its tangled alleys decorated in festival streamers where the aroma of sizzling sardines wafts from every corner.

It’s too hard to resist and before long we’re tucking into sardinhas assadas (grilled sardines) washed down with plenty of sangria as we heatedly discuss our favourite Marchas contestants.

The Marches Populares kicks off five days of celebrations in Lisbon, when the always lively city is even more boisterous.

The festivities are dedicated to Saint Anthony, who was born in Lisbon’s Alfama barrio in 1195.

The Franciscan friar was a passionate preacher devoted to the poor and armed with a gift for converting heretics. He’s also been known to help those who have lost something.

Taking the canary yellow No.28 tram up one of the city’s seven hills, we pass kids playing football on the cobblestones between buildings draped with washing.

Soon we come to where ‘heretics’ once ruled Lisbon at Saint George’s Castle.

Boasting a prime location that overlooks the glistening waters of the River Tagus and surrounding the barrios below, it’s no wonder Castelo de São Jorge was the preferred residence to the Visigoths in the 5th century, the Moors in the 9th century, and the Christians in the 12th century, when King Alfonso Henriques ousted the Moors after a 17-week battle at the castle.

We lunch at the castle’s restaurant Casa do Leão, and after a typical Portuguese four-course meal and wine, I nearly roll down the hill to the Sé Cathedral, to confess to the sin of gluttony.

On this special day the Sé becomes the scene for not just one local wedding, but 16.

Saint Anthony is known as the matchmaking saint for helping people find love and fixing marriages. It’s an honour to be married on this sacred day. Inside the 12th century Romanesque church, a magical haze seems to enshrine the couples as the sun pierces through the stained-glass window of Saint Anthony.

Later I glimpse the saint himself, in the form of a statue carried tall above cheering Lisbonites in a procession that winds around the Sé and the Church of Santo António.

It turns out the winner of the Marchas is Marvila, not Alfama – but this didn’t stop the residents of Alfama from indulging in an all-night fiesta. After all, they’ve got the great Saint Ant looking out for them.

» Jo Cackett travelled with TAP Portugal (0845 601 0932). Fares start from £48 one way, including taxes.