A major campaign to persuade Londoners to holiday in Scotland kicked off yesterday with an open-air exhibition in the capital celebrating all things Scottish.

Celebrities including comedian Hardeep Singh Kohli, chef Nick Nairn and actors Clare Grogan and Alistair Mackenzie are heading up the weekend of cultural events including music, food and entertainment.

Kohli, who recently began a stint as a BBC reporter for The One Show, yesterday opened the London Gathering event, which is expected to attract around 7000 visitors over the weekend. Today Kohli was in the culinary marquee with Nick Nairn and award-winning chefs Shirley Spear and Michael Smith of the Three Chimneys on Skye.

VisitScotland, the national tourist board, has unveiled a 120-metre-long poster of Scotland's best scenery which will be displayed along the Embankment outside the London Gathering exhibition at the Inner Temple Gardens, Holborn, the public area of that ancient Inn of Court. It marks the start of a major advertising campaign in the London Underground and at King's Cross Station to show commuters that Scotland is a must-see holiday destination.

Alistair Gronbach, VisitScotland's head of marketing for the UK and Ireland, said the London Gathering was a "kick-start" to VisitScotland's campaign. He said: "Up until now we've been bombarding people in the northern three-quarters of Britain with marketing messages on television and cinema. We're gradually rolling down the country.

"We've got clear market research from people who say they know Scotland has nice scenery, but they don't know what else they can do here."

The giant poster was used in another successful campaign in London two years ago and is in the Guinness Book Of Records as the longest-ever poster.

Gronbach said VisitScotland advertising would be going up in London Underground stations tomorrow and would run as part of its six-week marketing campaign. He said that the adverts would "contrast the contemporary and traditional sides of Scotland."

"We want people to look at Scotland in a different way," he said. "We'll also be running ads on satellite TV and in cinemas in London and the Midlands with adverts on the festivals and events we have, and the adventure sports in Scotland."

Sandi Thom performed her hit single I Wish I Was A Punk Rocker at the London Gathering yesterday, and she will take to the main stage again today before headliner Eddi Reader.

She said: "There's a really good crowd here. Eveyone was singing along having a good time. I've been having a look around the exhibition and it looks great. Everything that's Scottish is here, like whisky and haggis so it's like having a little bit of home.

"I know from my own experience that a lot of people like going up to Scotland for the festivals we have, like the Edinburgh Festival and things like T in the Park. People in London are always looking for a bit of an escape from the rat race and I think Scotland definitely offers that."

She went on to say: "I'm really excited about playing before Eddi Reader, because I used to do covers of her songs, so it will be nice to hear her sing them."

There will also be a ceilidh and fashion marquee as well as a whisky and literary tent, where writers AL Kennedy and Christopher Brookmyre will hold a question and answer session.

Scot Gardiner, managing director of the London Gathering, said: "This will be the first event of its kind to be brought to the capital. We hope to inject a taste of modern, contemporary Scotland into the southeast and beyond."

Scottish tourism supports 200,000 jobs in 20,000 diverse businesses, which represents around 9% of the country's employment. The industry generates revenue of over £4 billion a year.