Jeremy Corbyn poses 100th Prime Minister's Question
Jeremy Corbyn chose further education cuts as the subject of his 100th Commons question to David Cameron.
The Labour leader said that on his 99 previous questions he has been "unclear or dissatisfied with the answer".
But he pressed on with a crowd sourced inquiry from a "Callum" on cuts to the funding of sixth form and further education colleges.
Mr Cameron disputed Mr Corbyn's claims but congratulated him on reaching "100 not out".
The prime minister said that his survival was welcomed across the House of Commons.
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Mr Corbyn has attempted to introduce a less confrontational style at the weekly half hour session, and to ask questions sent in by members of the public, since he took over as Labour leader last September.
He is allowed six questions to the prime minister each week, when Parliament is sitting and Mr Cameron is in the country.
BBC analysis shows nearly half of Mr Corbyn's questions have been on welfare or health, with none on immigration.
He asked what is believed to be his first question on the economy at Wednesday's session, saying: "The construction output in Britain has shrunk for two consecutive quarters now, surely this is a matter of concern.
"Isn't this really a bit of a sign that this economic recovery is being constructed on sand?"
The PM said the government wanted "to see every part of our economy growing", but he added: "If you look at our construction plans, because we've got a strong economy we're able to commit to HS2, we're able to commit to the biggest road programme since the 1970s, the largest rail programme since Victorian times, together with huge infrastructure projects in energy and in other areas.
"Those things are only possible because we've got a strong and growing economy."
Mr Cameron warned that Labour would "wreck the country's finances" and put up taxes for low and middle earners.
The Labour leader then accused Mr Cameron of holding back Britain by cutting skills training and investment.
Mr Cameron claimed Labour had created instability in the economy while in government and failed to build enough houses - and disputed Mr Corbyn's figures on apprenticeships, which he claimed had seen a big increase in funding.
In a wide-ranging set of questions, Mr Corbyn also highlighted new figures from children's charities showing council spending on children and young people has been cut by £2bn.
The Labour leader said the reductions came at the same time as Mr Osborne cut corporation tax to the lowest level in the G7.
"Doesn't this demonstrate a wrong choice by the prime minister?" Mr Corbyn asked.
Mr Cameron hit back, accusing Mr Corbyn of making a "political point" instead of acknowledging that corporation tax receipts had increased by 20%, giving the Government more money to spend on services.