Anti-poverty campaigners are preparing to protest Barclays' annual general meeting on Wednesday amid evidence that the bank's commodity speculators are contributing to soaring global food prices.

A report by the World Development Movement (WDM) campaign group has named Barclays' investment banking division, Barclays Capital, among the top three food commodity traders worldwide, alongside US firms Goldman Sachs and Morgan Stanley.

BarCap is Britain's largest food commodities trader, and the WDM accuses the company of profiting at the expense of the world's most vulnerable, making substantial gains by speculating on food price fluctuations. This has lead to price instability and a sharp increase in the cost to the consumer of staple foodstuffs, with the poor in developing countries invariably the hardest hit.

The World Development Movement's director, Deborah Doane, commented that, "The lack of transparency in these markets bears worrying resemblance to the behaviour that led to the 2008 financial crash. Like any irrational asset bubble, the investors pile their money in for short-term profits, in spite of the consequences."

The precise value of food commodity trading to Barclays is difficult to pinpoint, however the WDM report estimates that such trades netted the company up to £340 million in 2010 alone.

The bank refused to comment on the report, but released a statement saying that its role amounted to acting as an "intermediary" on behalf of its clients. It continued, "Barclays Capital conducts a variety of investment banking activities to help our clients across asset classes and geographies."