David Cameron has come under pressure to launch an inquiry into why people are turning to foodbanks as demand for emergency supplies continues to surge.
More than 350,000 people received a three-day food package from the Trussell Trust between April and September, three times as many as the same period last year.
It has written to the Prime Minister calling on him to look into the "scandalous" problem of food poverty, warning some foodbank recipients are so poor they have returned produce that needs cooking because they cannot afford the electricity to heat it up.
Trussell Trust executive chairman Chris Mould said: "We said in April that the increasing numbers of people turning to foodbanks should be a wake-up call to the nation, but there has been no policy response and the situation is getting worse. The level of food poverty in the UK is not acceptable.
"It's scandalous and it is causing deep distress to thousands of people. The time has come for an official and in-depth inquiry into the causes of food poverty and the consequent rise in the usage of foodbanks.
"As a nation we need to accept that something is wrong and that we need to act now to stop UK hunger getting worse."
Earlier this year, Chancellor George Osborne suggested f oodbank use had increased " because people have been made aware of the foodbank service through local jobcentres".
But the Trust has echoed concerns that some households will have to choose between eating and heating this winter as they struggle to cope with the rising costs of food and energy.
It also highlights the impact of welfare reforms that came into force in April, reporting an increase in referrals as a result of the so-called "bedroom tax".
Mr Mould said: "Problems with welfare are not new, they have existed for years, but the reality is that when welfare provision breaks down, people go hungry.
"We're talking about mums not eating for days because they've been sanctioned for seemingly illogical reasons, or people leaving hospital after a major operation to find that their benefits have been stopped or delayed.
"It's not right that so many more people are now being referred to foodbanks due to problems with welfare, especially as much of this is preventable.
"This is not about pointing fingers, it's about finding solutions. That's why we believe an inquiry is now essential."
Chris Johnes, Oxfam's UK poverty programme director, said: "These figures lay bare the shocking scale of destitution, hardship and hunger in the UK.
"It is completely unacceptable that in the seventh wealthiest nation on the planet, the number of people turning to foodbanks has tripled.
"Oxfam welcomes The Trussell Trust's call for the Prime Minister to launch an urgent inquiry into why people are forced to turn to foodbanks."
TUC general secretary Frances O'Grady described the figures as "shocking".
She said: "The Chancellor is talking up a recovery - but for who? These new figures show that, despite trying desperately hard to make ends meet, hundreds of thousands of people still can't afford to put food on the table for their families.
"Welfare reforms like the Bedroom Tax have pushed more households into food poverty."
A Government spokesman said: "We have taken action to help families with the cost of living, including increasing the tax-free personal allowance to £10,000 which will save a typical taxpayer over £700, freezing council tax for five years and freezing fuel duty.
"The Trussell Trust itself says it is opening three new foodbanks every week, so it's not surprising more people are using them. They also agree that awareness has helped to explain their recent growth.
"The benefits system supports millions of people who are on low incomes or unemployed and there is no robust evidence that welfare reforms are linked to increased use of food banks.
"In fact, our welfare reforms will improve the lives of some of the poorest families in our communities with the Universal Credit making three million households better off - the majority of these from the bottom two fifths of the income scale."