Duncan Smith 'has insulted thousands of A-level students'

Iain Duncan Smith was accused of insulting thousands of school pupils last night by suggesting A-level passes might be worthless.

The Tory leader's attempt to attack the Government over the A-level marking fiasco backfired when he told Tony Blair at Prime Minister's Question Time: "Faith in A- levels has been shaken to the core – nobody even knows whether they are worth the paper they are written on."

Later, Mr Duncan Smith's aides sought to calm the storm over his remarks and rejected Labour claims that he had scored "a spectacular own goal". They insisted he was citing the views of Mike Tomlinson, the former chief inspector of schools, who after his inquiry into the A-level crisis said he still did not know "what the standard ought to be".

But Mr Blair accused the Tory leader of making a "gross insult to teachers and pupils up and down this country". He said: "It is absolutely wrong that they should have been put in that position.

"We accept full responsibility for it, but to say that A-levels and [to] the students who have got those A-levels that they are not worth the paper they are written on is totally irresponsible."

Estelle Morris, the Secretary of State for Education and Skills, wrote to Mr Duncan Smith demanding that he apologise, and withdraw his "absolutely deplorable and shameful" remarks. She said students would be "horrified" after they had "worked hard and long for their achievements". Phil Willis, the Liberal Democrats' education spokesman, joined the attacks. He said: "We will not be repeating the outrageous slur made by the quiet man today."

John Dunford, general secretary of the Secondary Heads Association, who spoke at last week's Conservative Party conference, denounced Mr Duncan Smith's remarks as "crass". He said: "It's a simplistic reaction to the complex problem investigated by Tomlinson. He is not going to make any friends among the students who have worked hard for these exams."

Doug McAvoy, general secretary of the National Union of Teachers, accused Mr Duncan Smith of "undermining the success of this year's A-level students and the confidence of those taking the exam next year".