The number of people using food banks in Kent and Medway has trebled, figures out today show.

Charity the Trussell Trust revealed almost 3,800 people received a three-day food package at its county sites between April and September.

That total – for food banks in Ashford, Gravesham and Medway – compares to just 856 in the same period the previous year.

The Trussell Trust wants the Prime Minister to open an inquiry into why so many people are using them.

It said people at food banks have even started giving back food that needs cooking – because they cannot afford to turn on the electricity.

Speaking in the Commons today, David Cameron said the government is helping the most vulnerable in society.

Nationally, more than 350,000 people received handouts from Trussel Trust food banks in just six months.

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 food banks.

"As a nation we need to accept that something is wrong and that we need to act now to stop UK hunger getting worse."

The organisation said food prices have risen by 12.6% above inflation over the past six years and rising energy prices this winter are likely to see more people forced to choose between eating and heating.

The number of people using the Trussell Trust's Ashford food bank rose from 230 in the six months to September 2012 to 847 in the same period this year.

In Gravesham, the number rose from just 19 to 1,202. And in Medway, the number of food bank users rose from 607 to 1,744.