Booking platforms such as Tripadvisor face growing pressure to reveal the employment practices of the Spanish hotels they promote, as a cleaners’ activist group launches a name and shame campaign aimed at rooting out exploitation in the tourism industry.

The campaign has been launched by the Barcelona branch of Las Kellys, a play on las que limpian (those who clean), a nationwide group of hotel cleaners who are fighting against outsourcing which has led to working conditions that in many cases have been described as virtual slavery.

Speaking at the launch of the campaign in the Catalan parliament, Vania Arana, the group’s spokeswoman, said it was creating a seal of quality for hotels that followed good practices in the firm belief that most clients would not want to stay in a hotel where domestic workers, the vast majority of whom are women, were paid as little as €2 to clean a room that cost €200 a night.

The group has been in touch with Tripadvisor with a view to it carrying the seal of quality on its website. Tripadvisor did not respond to a request for comment.

The leftwing political coalition En Comú Podem has proposed legislation that would outlaw bad practices in the industry. “We can’t wait until this happens so we are initiating this campaign of good practices in hotels,” Arana said. “We will invite hotel managers to let us carry out an inspection so that they can receive this seal of approval.”

The group plans to promote hotels that obtain the seal on social media while exposing those with bad practices. In addition to their trademark bright green T-shirts, in their role as hotel inspectors, Las Kellys will also don green safety helmets.

Under labour changes passed by the recently deposed People’s party government, hotel cleaners have seen their wages cut by as much as 40% and their workload increased as hotels outsource their jobs to agencies.

The women are demanding that hotels revert to employing them directly under the national agreement which guarantees them a monthly wage of €1,200 (£1,060) for a 40-hour week, instead of outsourcing the work.

While the outsourced contracts often appear to offer the same pay and conditions, there is a catch: they also specify how many rooms have to be completed during a six-hour shift, on average between 25 and 30, which is not humanly possible.

As a result, the workers put in unpaid overtime to meet their quota, bringing their hourly rate down to €3 or €4. If they fail to meet their quota they are sacked.

Virtually all the workers complain of health problems, such as back pain and arthritis, and many say they only get through their shift on a diet of painkillers.

Speaking at the press conference, Yolanda López of En Comú Podem called on the Catalan government to encourage the creation of quality jobs and penalise those who “use subterfuge to create precarious working conditions”.

Las Kellys have come to symbolise the increasingly precarious Spanish job market, where more than 90% of contracts signed since the 2007 financial crash are either part-time or short-term.

• This article was amended on 6 July 2018 to use a job description in line with Guardian style on gender.

