People who spit in the street will be forced to clean up or face an £80 fine, police in north London have said.
The initiative is particularly aimed at chewers of paan
The clampdown is particularly aimed at chewers of paan, a tobacco leaf-based mixture, which authorities blame for staining pavements in central Wembley.
Posters and leaflets are being handed out warning spitting is "unhygienic" and an "act of anti-social behaviour".
"Paan damages walls and pavements and costs taxpayers thousands of pounds a year to clean," said Ch Insp Raj Kohli.
Paan spittle hotspots are Ealing Road and part of the High Road near St Johns Road, according to Brent Council.
"Spitting leaves the pavements looking dirty and unpleasant and there has been quite a lot of local concern, particularly in health terms," said council officer John McSwan.
"The initiative is particularly aimed at people spitting 'paan' which leave stains on pavements which are extremely difficult to remove," he said.
Council officers will join Wembley Central police officers to help identify spitters and take part in spittle clean-up operations.
Local paan retail outlets have received information packs and advised about the forthcoming enforcement activity.
Police said those caught spitting, which also includes chewing gum, would be given the option of cleaning up their spittle or receiving an £80 penalty notice.
"This sort of anti-social behaviour has to stop if Wembley wants to become the iconic landmark of London it has all the potential to be," said Mr Kohli.