Basic pay in factories that cut and sew fabric for budget chains could be just £8 a month for an 80-hour week, investigation for the charity War on Want found.

Overtime payments of around 4.40 a month meant some workers were receiving just 16.25 a month for a seven-day week - 5 cent an hour. On top of that, workers complained that joining a trade union was banned and bosses cheated them of overtime pay. Beatings and sexual harassment were also said to occur.

War on Want interviewed 60 workers from six factories for its report, Fashion Victims, published on the day of the annual meeting of Associated British Foods, which is expected to report booming profits at Primark, which has its headquarters in Dublin and is run by Dublin retailer Arthur Ryan.

The charity chose the six factories at random to highlight conditions at suppliers for the budget end of British fashion. All six supplied Asda, four Tesco and three Primark.

Workers complained they were routinely defrauded of overtime payments and there was a pervasive air of deprivation.

Primark said that if War on Want provided details of the factories, it would investigate. "Our low prices are the result of technology, efficient distribution and supply, bulk-buying and the fact that we spend almost nothing on advertising, " said a spokesman.