Cleaners at London's School of Oriental and African Studies (Soas) will today begin a 48-hour strike in protest over "systematic discrimination" from bosses.

The workers - employed by outsourcing firm ISS - receive less sick pay and fewer holidays than other staff and are denied access to the school's pension scheme.

Managers have refused to bring the cleaning staff in-house despite a long-running campaign by public-sector union Unison.

Unison assistant branch secretary Ezequiel Kramer told the Star that management has been reluctant to negotiate and showed no respect for its cleaners.

"Soas has effectively a two-tier workforce," said Mr Kramer.

"These disparities are unacceptable."

Multinational company ISS is known for bullying dissenting workers. Director Paul Cronin has threatened to take away the London Living Wage which cleaners won through industrial action back in 2008.

Soas cleaner Lenin Escudero hoped the industrial action will make management aware of the importance of his work when the school becomes increasingly dirty throughout the strike.

"We are not afraid anymore," he said defiantly.

"We are proud of ourselves. We brought the Soas community together, the real community - workers, students, lecturers."

Many Soas lecturers are said to have cancelled classes for March 4 and 5 in solidarity with the striking cleaners.

Soas students have often refused to cross picket lines and many are set to protest outside the school's main building in defence of cleaners' rights.

"We feel very confident with all this support," said Mr Escudero.

"We hope the management learns the real meaning of equality and justice."

Back in 2009 ISS tricked its staff into attending a "meeting" within Soas premises which served as an ambush for a Border Agency raid.

Seven people, including a pregnant woman, were deported shortly after.

Students and staff campaigned for the room where cleaners were held to be renamed Lucas Lecture Theatre - after the son of the deported woman.

Soas management renamed the room after the son of a wealthy donor instead.