Londoners are being offered the chance to get paid to spend sunny weekends in the park - to watch what picnickers do with their litter.
Environmental charity Keep Britain Tidy has launched the project in a bid to better understand the issue of "abandoned picnics" in the capital's green spaces.
It is recruiting eight observers for four shifts on certain weekends in August and September to monitor how people deal with their waste.
Recruits will be paid £11 per hour, plus a £40 bonus on completion of all four shifts.
The advert warns applicants to be flexible, as they will only be needed on sunny days and their shift could be postponed due to bad weather.
Successful candidates will receive a day of training on Keep Britain Tidy's research methodology, and will be required to submit all their data via a spreadsheet.
A spokeswoman for the charity said: "This is not surveillance, it's anonymous - it is just watching how people behave in the space.
"Then we will think what could we do to change that behaviour and think about putting different kinds of solutions in place.
"There could be a number of things we could do, such as putting some signage in certain places."
She emphasised that the charity's aim is only to gather data, and is not focusing on any individual members of the public.
Britain has one of the highest levels of litter in Europe and councils across the country spend an estimated £1 billion every year cleaning up.
London's most popular parks are some of the worst hit, especially on warm days.
Hackney Council now runs special "enforcement days" with its own officers and police to fine people caught littering, selling nitrous oxide and urinating in public.