London turned green this afternoon as Irish dancers, revellers and pets in fancy dress marched through Trafalgar Square to mark the beginning of St Patrick's Day celebrations in the capital. Revellers donned traditional Irish costumes as they jigged through the centre of London to the sound of ceilidh music, bagpipes and banging drums. There was a vivid array of colours on show, with festival-goers sporting bright wigs, outlandish hats and resplendent outfits. Scroll down for video . A man shows off a pair of shamrock glasses - a symbol of Ireland - to celebrate the lead-up to St Patrick's Day in London . A dog kitted out in a green Ireland football jersey joined the festival as revellers marched through Trafalgar Square this afternoon . A group of dancing women twirl in central London as part of early St Patrick's Day celebrations in the capital . Two women leap in the air in front of a rather bashful photographer as they danced along Trafalgar Square this afternoon . A group of people play the bagpipes, flanked by the London Wexford Association - a group celebrating its 60th anniversary this year . The parade is the lead-up to the main event on Tuesday when 150,000 people are expected to congregate in London for the 14th annual St Patrick's party. It is being headed by former world champion boxer Barry McGuigan and features floats representing all 32 counties of Ireland. The festival begins at Green Park station at noon and then meanders along Piccadilly, Lower Regent Street, the Mall and Cockspur Street before heading up to Trafalgar Square and eventually finishing on Whitehall. A group of three get into the spirit of things by donning Guinness party hats and badges cheekily saying 'Kiss me, I'm Irish' There was a vivid array of bright colours on show, including this resplendent outfit worn by one daring festival-goer . Some revellers dressed up as Catholic priests for the St Patrick's parade, while others wore traditional green and white hats . The parade is being headed by former world champion boxer Barry McGuigan and features floats representing all 32 counties of Ireland . A woman dressed as a leprechaun to mark the beginning of the St Patrick's Day celebrations in London . Onlookers take pictures of the mechanical 5th century bishop as it wheels its way through central London this afternoon . It will include performances by the cast of smash-hit West End musical The Commitments, Lord of the Dance and rapper Lethal Dialect. Mayor of London Boris Johnson said: 'It's a pleasure to once again be supporting one of the greatest St Patrick's Day celebrations anywhere in the world. 'Our free event in the heart of the capital is a terrific opportunity for Londoners and visitors to embrace the traditions of Ireland, and celebrate everything the Irish have given to the city and continue to do.'
Irish dancers, revellers and pets in fancy dress marched through Trafalgar Square for St Patrick's Day Parade . Part of build up before Tuesday's main event when 150,000 people are expected for 14th annual St Patrick's party . Headed by former world champion boxer Barry McGuigan and features floats representing all 32 counties of Ireland .