Tesco, the supermarket giant with a market cap of £25,383m, has ignited outrage across Britain with a job advert which offered prospective employees a permanent night shift - with no wages. Tesco has claimed the advert, which said the only payment would be job-seeker's allowance and expenses, was a "mistake". In a statement from the UK's supermarket chain said: "The advert is a mistake caused by an IT error by Jobcentre Plus and is being rectified. "It is an advert for work experience with a guaranteed job interview at the end of it as part of a government-led work experience scheme. We take our responsibility as Britain's biggest private sector employer seriously." The statement did little to quash the public's fury, however, with many taking to social networking site Twitter to vent their anger. One twitterer, known as Bristle KRS, posted that "If Tesco want workers without wages, we demand goods without payment!"The job post, for a position in an East Anglian store, is just one of many offering unpaid roles under the government's 'workfare scheme', which has proved to be more than a little controversial. The scheme was set up in a bid to tackle long-term unemployment by forcing unemployed but able-bodied members of the public to take on work experience. Anyone who refuses runs the risk of losing their unemployment benefit. Sam James, a spokesperson for campaign group Right to Work, said: "This is another example of working-class people being forced to pay for a crisis created by the greed of the rich."In a more positive story, the supermarket chain has donated £0.5m to a helpline dedicated to supporting Alzheimer's sufferers and their carers. The Alzheimer's Society, which has seen the number of calls it receives soar, will now be able to open at weekends from September. In 2011 the charity received 31,260 calls, significantly up from 24,777 the previous year. Tesco's corporate responsibility director, Ruth Girardet, said: "It's thanks to our passionate staff and customers, who have been busy raising funds all year long, that we are able to donate this money and help many more people affected by dementia."NR