NHS test-and-trace units run by G4S have cut the pay of some workers by up to 5% in the wake of a new contract from the government that specifies they should receive the real living wage. The affected workers are part of a group of 1,000 who work at mobile Covid-19 testing units at about 100 sites around the country, and are employed by G4S via the HR GO recruitment agency. Some were told their hourly pay rate would drop from £10 an hour to a maximum of £9.50 an hour outside London, a cut of 5%. Those in London will drop from a maximum £11 an hour to £10.85, a 1.4% cut. In a note sent to staff, G4S said the pay change was the result of a new 12-month contract with the government, under which it was required to pay all staff the real living wage, an independently verified minimum of £10.85 in London and £9.50 elsewhere. While this will result in a pay rise for some workers, who earned as little as £9.30 an hour, others contacted the Guardian to say their pay has been cut from £10 an hour. The letter to workers said the previously higher rates of pay reflected “uncertainty around how long [the government] would require sites to operate”. “The longer-term nature of the [new one-year contract] provides more certainty and therefore the real living wage is more appropriate for the longer term role,” it said. Sara Gorton, the head of health at the Unison union, said: “Living wage clauses are designed as a minimum – not an excuse for some greedy contractors to reduce pay.” Workers are also concerned at not being paid for travelling time or petrol expenses to attend the testing centres. Some said they were asked to report to a variety of sites each week which could be as much as an hour’s drive away from home or from their main testing centre, and they were not reimbursed for petrol costs. Some workers said they often travelled for two hours a day, and their daily rate only allowed for one hour of travelling time after working at least seven-hour shifts at the testing centres. If an hour’s extra travel time were taken into account, they were left with only £8.44 an hour compared with the legal minimum for over 23-year-olds of £8.91. If the cost of petrol was taken into account, workers were left with even less. Workers were warned they would have to drive up to 50 miles a day when they took on the job. Employers are not legally obliged to pay ordinary commuting time or expenses. However, one said: “The reduction in pay for temporary test-and-trace staff, who are currently expected to travel long distances at their own expense, means that thousands of workers at mobile sites are effectively being paid less than the minimum wage while exposing themselves to symptomatic members of the public.” Another said: “I’m having to be more careful with money, especially having to travel so far some days. The change in pay doesn’t sound like much but you do notice the difference. I am having to dip into savings to cover life expenses.” G4S said workers’ claims about low pay were unfounded. It said they were paid for an eight-hour shift and were on site for an average of six hours. “These claims are unfounded. All our workers are paid the real living wage for all hours worked, including overtime, in accordance with the law and government guidelines,” a spokesperson for the company said. “The only travel that our workers do is their commute to and from their place of work. In line with general market practice in the UK, we do not pay employees for commuting time. For our mobile testing unit (MTU) workers, which is an area-based role with no fixed location, the average journey is less than half an hour each way. “Our MTUs complete thousands of journeys across the country each month and 99% of round journeys in the last month were less than two hours.” Michael Newman, an expert in employment law at Leigh Day, said that the set-up for mobile testing workers was “quite removed from the standard situation where a person has one workplace, or even the travelling worker who is constantly on the move”. He said that by moving the work site day by day, or week by week, G4S did not enable workers to organise their commute and have any control over their travel costs. “Employers are responsible for paying the expenses of their employees, and any journey that is not an ordinary commute, and is necessary for the work, should be reimbursed,” he said. A spokesperson for HR GO said: “HR GO has paid our workers in line with the terms of our current contract with G4S.