Outsourced workers to take part in series of walkouts this week over pay and conditions

London will be hit by a wave of Halloween strikes as hundreds of cleaners, park attendants and cafe workers fight for better pay and conditions.

The United Voices of the World union said it would be coordinating weeks of industrial action by outsourced workers who were demanding the London living wage and full sick pay.

The workers say they have to work when they are ill because they receive only £94.25 a week in statutory sick pay, which does not kick in until they have been off work for four or more days in a row.

Central London green spaces, including Hyde Park, Kensington Gardens and St James’s Park, will go untended as park attendants and cleaners employed by the outsourcing firm Vinci take industrial action on 31 October. They are demanding a pay rise from £8.21 an hour to the London living wage of £10.55, as well as occupational sick pay and full statutory holiday entitlement.

The Royal Parks workers will be joined by cleaners from an office on Gray’s Inn Road that houses Channel 4 and ITV. The cleaners, who work for the outsourcing firm City & Essex, want full sick pay and more annual leave.

Genevive Boohene, a Ghana-born Royal Parks cleaner, said: “I have worked at the Royal Parks for 24 years, but these poverty wages mean that, like many of my colleagues, I’m living a hand-to-mouth existence. We are denied occupational sick pay, many of us do not receive our legal entitlement to holidays, and managers ignore our suffering and concerns.”

Workers at University of Greenwich cafe, who are fighting to be brought in-house and given the same terms and conditions as other workers at the university, will strike on Monday and Thursday. They say their pay is too low – below the London living wage – and they are forced to work when ill because they only receive the statutory minimum sick pay from the outsourcing firm BaxterStorey.

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Maureen Sandbach, people director at BaxterStorey, said: “The welfare of our colleagues is imperative and we are committed to working with team members and trade union members to come to a resolution and pay real living wage. BaxterStorey operate an occupational sick pay scheme commensurate with length of service.”

More than 150 cleaners, caterers and porters at St Mary’s hospital, which is part of Imperial College NHS healthcare trust, will also take action on Monday, Tuesday and Thursday. The workers, who are all outsourced to Sodexo, say they are paid far less than in-house NHS workers in similar jobs and only receive statutory sick pay, and are not allowed to use NHS canteens and staff rooms.

One striking cleaner said: “I work 55 hours a week just to cover my rent. This [St Mary’s] is my home, I spend more time here than in my house. Yet I am treated like a dog and made to feel like dirt.”

Sodexo said it had already agreed to pay the independently verified London living wage from April and remained open to “negotiation and arbitration”. In a statemened it added: “We have been working with our people and recognised trade unions to address their concerns. We are disappointed that some staff have voted to take industrial action.”

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The strikes come as hundreds of cleaners, porters and security workers at University College London outsourced to Axis and Sodexo vote on whether to strike for improved sick pay, holiday pay and pensions. The results of the ballot will be finalised on 5 November but the workers plan an earlier protest at UCL for this Wednesday.

The Independent Workers Union of Great Britain (IWGB) say the action could be the biggest strike yet of outsourced staff in UK higher education. Up to 300 workers are demanding the same terms and conditions as colleagues directly employed by UCL.

Vinci and City & Essex did not respond to requests for comment. Axis declined to comment because of “client confidentiality”.