The most recent stage, which cost £2m, includes the Mayor urging people from across the nation to make the most of what London has to offer.
Data from retail analyst Springboard found footfall across the west end this year is down by almost a quarter (24%) compared to pre-pandemic levels.
The latest chapter of the Let’s Do London campaign aims to attract audiences outside of London with adverts across TV, radio and social media.
Before the coronavirus crisis, London was the third most visited city in the world with a tourism sector that accounted for one in five jobs in London, contributing almost 12% of the city’s GDP.
According to the Mayor’s office, when the campaign was first launched last year, it brought in an additional £81m in spending and 330,000 overnight visitors to the capital.
Earlier this year, the Mayor extended the scheme across the world when he launched in New York, the largest international campaign the city had ever seen.
It included £7m to encourage international tourists back to London, £2m to attract overnight UK visitors and £1m for reaching out to Londoners.
Khan said: “London is the greatest city in the world, with incredible cultural attractions, unique experiences and adventures to enjoy for a wide-range of budgets.
“This fantastic tourism offer helps to drive our economy by supporting businesses and jobs across the capital.
“I’m proud my Let’s Do London campaign has already helped to bring back hundreds of thousands of tourists back to London but I’m determined to show even more people across the country and the rest of the world, our capital is ready to welcome them.”
No better time
UKHospitality chief executive Kate Nicholls the variety of reasons for visiting London were as strong as ever.
She added: “It’s only right that, while inbound tourism makes its recovery, domestic holidaymakers get to experience London while it is a little more accessible than most summer seasons.
“With the brand new Elizabeth Line, our attractions open and a dazzling events calendar to plan around, there’s perhaps no better time to come to the capital.”