THE stage is set, the bunting is up, and the final potholes have been filled. Now, let the drama begin.

After 18 months of planning and preparation, the eyes of the world will turn to Yorkshire this weekend, as we host the largest annual sporting event on the planet.

Today and tomorrow, the Grand Depart of the 101st Tour de France will see 198 cyclists race through Yorkshire's cities, towns, villages and countryside, watched by crowds of up to four million along the route and a global television audience of countless millions more.

The event is costing Yorkshire £21 million, including £6 million on road repairs, but it is expected to bring an economic boost of more than £100 million, according to Welcome to Yorkshire chief executive Gary Verity.

Mr Verity, the man whose dream brought the Grand Depart to the region, said last night: “Our county is about to make history as we welcome the world’s largest annual sporting event, which will provide a major opportunity for thousands of our businesses to benefit now and into the future."

He said the economic benefit would be felt across several sectors and said: "The Tour is broadcast in around 190 countries, providing Yorkshire with global exposure, and together we will do all we can to maximise this opportunity.”

Kersten England, chief executive of City of York Council, called it a once in a lifetime event and said residents, groups, businesses and council staff had worked to ensure York's beauty and spirit would be remembered by the billions watching the race.

She said: "We’re already seeing the economic impact of this incredible event as people come here to cycle not only for the Tour de France route, but for the rest of the county. We should see a five-year uplift in tourism following the event - which is fantastic - but the real legacy will be about an increase in participation in seeing more people cycling more often across the region."

The peloton leaves Headrow in Leeds at 11am today, cycling in procession to Harewood House, where the official race will be begun by the Duke and Duchess of Cambridge and Prince Harry.

The route takes in 118 miles, through the Yorkshire Dales and then Ripon before ending in Harrogate around 4.30pm.

Tomorrow, up to 200,000 visitors are expected in York, virtually doubling the city's population for the day. The cyclists will set off from York Racecourse at 11am, to the city-centre at 11.20am, before leaving York via the A59 to Knaresborough, the Dales, and then on to South Yorkshire and Sheffield, including some of the toughest climbs in British cycling.

Festivities will continue throughout the day in York at spectator hubs and local parties and at the Racecourse, where 20,000 free tickets were snapped up within 24 hours of being released.

Yorkshire Ambulance Service has more than 1,000 medics, additional cycling paramedics and three air ambulances will be on duty over the weekend, and say extra staff have been drafted in to minimise the impact of a strike by Unite staff. Almost 1,000 police officers are on duty, as are 7,000 to 8,000 official Tour Makers and 3,000 to 4,000 stewards.

Kate McMullen, head of tourism body Visit York, said: "The sense of celebration and excitement around the Tour de France in York and Yorkshire is fantastic and we’re thrilled with the interest we’ve had from visitors as well as journalists and tour operators."

She said bookings were buoyant, with only a handful of rooms left in the city, and merchandise had been selling well. She said: "Hugely important for us is the legacy this will create; we’re seeing an unprecedented interest in cycling holidays and the world-wide media exposure for York and Yorkshire will benefit tourism for years to come."