...Commercial cleaning staff, usually women and migrant workers, complained of being frequently mistreated by employers, who often ignore obligations to provide holiday and sick pay, according to the new study by the Equality and Human Rights Commission (EHRC), The Invisible Workforce: Outsourcing and Employment in the Cleaning Sector...The report...cites disturbing examples of abuse of cleaning staff by agency bosses, and notes that often cleaners feel unable to report problems for fear of losing their jobs...The cleaning sector contributes more than £8bn to the British economy, and consists of around half a million workers, the report states...In London, migrant workers make up as much as 44% of the total workforce. Migrant workers' poor command of English and lack of knowledge about employment rights makes them particularly vulnerable to mistreatment...The EHRC has proposed a number of measures to improve conditions for cleaners...