The number of online searches for hotels in London fell by nearly a quarter during the Tube strike.
That's according to data from hotel search website Trivago.co.uk, which reported that searches from the UK fell 24%. Global searches for hotels in the capital were down 9%.
Searches for future hotel stays in London were down by just 4%, which suggested that the decline was as a result of the Tube strike and also limited to the strike, according to the company.
The industrial action began at 18:30 BST on Wednesday when members of the Rail, Maritime and Transport (RMT) union, the Transport Salaried Staffs Association (TSSA) and Unite walked out.
At 21:30 on Wednesday, members of the train drivers' union Aslef began their own 24-hour stoppage.
A spokeswoman for Trivago said: "It is extremely rare to see a significant decrease in travel interest to a city as large as London.
"With around 3,000 hotels as bookable via Trivago, a decrease of 24% is likely to have a significant effect on the city's tourism over the two-day period.
"The decrease in hotel searches is just one indicator of the effects of the Tube strike, with visitors relying almost solely on the Underground system in order to travel within the city."
The figures provided by Trivago compared searches for London hotels during this week's industrial action against the corresponding days during last week.