The trade union also blamed “the failed economic policies of George Osborne” after a new report revealed that up to 500,000 people in the UK rely on food banks.
The study by Church Action Poverty and Oxfam says benefit cuts, unemployment and the increased cost of living are to blame for the growth in hunger and poverty.
Unite’s general secretary Len McCluskey said:
“The original concept of food banks was that they should be a last resort safety net – but it now appears that they are becoming a way of life for hundreds of thousands of people through no fault of their own.
“The Tories may pretend that food banks are an affirmation of the so-called ‘Big Society’, but the fact that an increasing number of people are using them just to survive is a searing indictment of this government, whose polices are pushing thousands of families into grinding poverty.
“The Trussell Trust, the UK’s biggest provider of food banks, does sterling work, but it can’t be expected to pick up the tab for the failed economic policies of George Osborne and the divisive welfare ‘reforms’ of Iain Duncan Smith.
“The growing queues at the food banks are stark evidence that ministers need to reverse their failed polices and get a flatlining economy moving again – creating jobs and putting money into the pockets of ordinary people, and not into the coffers of the rich and powerful.”
The report recommends that the Commons Work and Pensions Select Committee conduct an inquiry into the relationship between benefit delay, error or sanctions, welfare reform changes and the growth of food poverty.
It also calls on DWP to publish data on a regular basis on the number and type of household who are deprived of their benefits by reason of benefit delay, error or sanctions; the numbers leaving and returning to benefits after a short period of time, and the number of referrals from Jobcentre plus staff to local food banks.
Mark Goldring, Oxfam's CEO, said: "The shocking reality is that hundreds of thousands of people in the UK are turning to food aid.
"Cuts to social safety-nets have gone too far, leading to destitution, hardship and hunger on a large scale. It is unacceptable that this is happening in the seventh wealthiest nation on the planet."
The Trussell Trust, which is the biggest provider of food banks in the UK, last month reported that more than 350,000 people turned to their food banks for help in the last year, almost triple the number who received food aid in the previous year.
Changes to crisis loan eligibility rules, delays in payments, Jobseeker's Allowance sanctions and sickness benefit reassessments are the most common benefit changes that led to people using food banks.
Niall Cooper, Church Action on Poverty CEO, and the report's lead author, said:
"The safety net that was there to protect people is being eroded to such an extent that we are seeing a rise in hunger. Food banks are not designed to, and should not, replace the 'normal' safety net provided by the state in the form of welfare support."