Tourism could provide up to 70% of an estimated £2bn economic benefit from London's 2012 Olympic Games, tourism minister Shaun Woodward said today.

The capital's hosting of the Games represented the biggest opportunity for British tourism in a generation but the industry had to act now to reap the full benefit, the minister said.

"The Olympic and Paralympic Games in 2012 provide the biggest opportunity for British tourism in a generation," Mr Woodward told a forum of tourist officials and Olympic organisers in London.

"To make the most of all the opportunities for future growth and prosperity that London 2012 brings, we must act now and lay strong foundations that will shape British tourism for generations to come."

Paul Deighton, chief executive of the London Organising Committee for the Olympic Games, added: "The Olympic and Paralympic Games will create a spectacular celebration of sport and culture in 2012. They will engage the whole world with this country in a way that has never been done before.

"They are a catalyst for getting so much done and for creating so many opportunities, both at Games time and as an investment in our tourism industry of the future."

Yesterday, former foreign secretary Jack Straw claimed the 2012 Games for his home county of Essex.

"Ethnically, this is really Essex," declared Straw, now leader of the Commons, on his first visit to the east London Olympic park in Stratford.

"The rest of the City of London does not really understand the great value of Essex. There are lots of jokes about Essex but it is a place of great self-confidence. People are really lively."

Mr Straw, who chairs a Cabinet committee overseeing preparations for the Olympics, was born in Buckhurst Hill, went to school in Brentwood and was raised in Loughton.

"Having the Olympics is fantastic," he added. "It will be a chance to show the world how great this city is. It will be a chance to show that all those jokes about Essex girls and people are wrong."