It was the day the Nasty Party showed its true-blue colours - by sneering at the plight of hungry families forced to rely on food banks.

Tory MPs laughed and jeered as they were told how some hard-up shoppers were so desperate they fought to snap up discounted items in supermarkets.

Astonishingly, all the Government ministers from the responsible departments - including Work and Pensions Secretary Iain Duncan Smith - sneaked out after just an hour of the crucial Commons debate.

By then a cowardly IDS had already ducked questions, putting forward his deputy instead.

In one of the most shameful episodes ever witnessed in Parliament, Tory backbenchers sniggered and hooted as Labour MP Fiona MacTaggart told of shocking scenes at her local Tesco in Slough, Berks, as people battled over cut-price fruit and veg.

She said the store had now been forced to draft in extra security.

Almost drowned out by mocking Tory MPs, she asked: "Isn't that a shocking sign in the 21st century?"

Senior Labour politicians later described the Tories' callous reaction as "shameful" and "a total disgrace".

Labour MP Jamie Reed said: "I regret to say the laughter from the Government benches says more about this issue than words ever could."

His colleague Barry Gardiner said it was "extraordinary" to see Mr Duncan Smith smirking as it was pointed out that half a million people are now using food banks.

And The Trussell Trust, the nation's largest provider of food banks, said it was "disappointed" by the attitude of those who jeered.

Labour had called the debate after nearly 150,000 people signed a petition backed by the Mirror, the Unite union and The Trussell Trust calling for an inquiry into the growing dependence on food aid.

But Mr Duncan Smith refused to answer for the Government, leaving it to his deputy, Esther McVey.

And in an ill-judged speech, she sparked fury by claiming it was a good thing that more people were turning to food banks.

Incredibly she insisted: "It is positive that people are reaching out to support other people."

She went on: "In the UK it is right that more people are going to food banks because as times are tough, we are all having to pay back this £1.5trillion debt personally. We are all trying to live within our means, change gear and make sure that we pay back all our debt."

Labour veteran Sir Gerald Kaufman described her speech as the "nastiest" he had heard in his 43 years as an MP.

Labour's Lilian Greenwood added: "They are the nasty party through and through. She doesn't get it and won't take responsibility."

Shortly after Ms Mcvey's performance, Mr Duncan Smith scurried from the chamber, followed by an number of other senior Tories.

Speaker John Bercow said he had no power to stop them, but said the view that it was a disgrace there was no minister there "may be widely shared". Shadow Environment Secretary Maria Eagle said the increasing need for food banks was a damning indictment of Government policy.

She added: "Since April this year more than 500,000 people have relied on assistance from the 400 food banks run by The Trussell Trust charity, double the number of food banks compared to this time last year." She added: "It's a scandal which is getting worse and the Government now has the humiliation of the Red Cross helping to collect and distribute food aid in Britain for the first time since the Second World War."

Former Labour Cabinet minister Paul Murphy told the Commons he had never seen such poverty in his 40 years as a Welsh politician, apart from during the 1984 Miners' Strike.

Shadow Work and Pensions Secretary Rachel Reeves told the House: "It's a tale of two nations - tax cuts for the rich, food banks for the poor."