Draft House, Masala Zone and Polpo are among the seven latest restaurant groups to be hit by criticism for their service charge policies.
Cau, Fortnum & Mason, Banana Tree and Mango Tree were also on the list of restaurant brands to come under fire in a report by the Evening Standard.
The restaurant groups, which between them have around 50 sites, all add 12.5% in service charge to the bill but according to workers, that cash is not given to customer-facing staff on top of their wages.
The money is evenly distributed to all restaurant staff through a tronc system, where tips and service charges are collected in a central pool before being handed out.
A storm of negative publicity for several restaurant groups including PizzaExpress, Bill's, Cote, Las Iguanas and Turtle Bay, which were accused by unions and former employees of "misleading" customers over the level of service charge and tips they were withholding for administrative charges and other reasons, prompted business secretary Sajid Javid to launch a review into the practice.
Polpo, founded by Russell Norman and Richard Beatty, told the Evening Standard it welcomed the review of the "confusing and disparate area of restaurant service charge", and added: "If a better scheme is proposed we will support and implement it."
Argentine restaurant brand Cau said: "The way the service charge is distributed depends on the individual's pay rate, seniority and job title. One hundred per cent of service charge is distributed. Any additional tips go directly to that member of staff."
Business owners claim they have effectively been forced to run troncs since 2009, following a HMRC ruling that stated staff could not be paid the minimum wage from service charges but that anything above that amount can be paid from the charges.
A former worker at pub chain Draft House told the Evening Standard
âAt busier times of year the troncmaster has always retained some service charge to allow for the boosting of staff pay during quieter periods and to also ensure that all staff receive full total pay when they are on holiday.â
Far East restaurant chain Banana Tree has allegedly stopped evenly distributing the 12.5% service charge to staff. Pay rose from £6.50 an hour to £7 an hour but staff apparently did not get to take any additional service charge.
A similar policy operates at Fortnum & Mason, which said: âIt ensures market rates for entry-level staff, it fosters career development, and allows the opportunity to reward individual performance.â
At London Victoria restaurant Mango Tree, staff said they saw none of the service charge, however the company denied this.
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