Work Programme puzzle

It started with a statement from the redoubtable Margaret Hodge MP, chair of the Public Accounts Committee.  She is angry at the failure of the Work Programme to help the people it was supposed to help, especially those on ESA.  There has been no improvement, she said, since the PAC examined it in 2012, and providers are spending only 46% of what they were meant to spend supporting each client.  Then comes the puzzling bit: "It beggars belief that the Department expects to pay at least £31 million in bonuses to all of its contractors despite their poor performance - even the Newcastle College Group whose contract has been terminated will receive a bonus."
I confess to never having heard of these bonus payments.  There was little enlightenment from an article by Rajeev Syal in the Guardian.  He adds some more figures, but gives the bonus as £25m (and then £31m), while calling it "incentive payments", and saying that the National Audit Office "has discovered that flaws in the work programme contracts meant that the [DWP] is obliged to make incentive payments to even the worst performing providers."  The figure isn't dependent on results.
Still confused, I looked at a piece from Sky News.  It's clearer.  And there's an interesting paragraph: "Figures for the most recent group to have gone through the scheme showed just 32% of participants found jobs - still below the DWP's minimum performance level of 33% and well below its original forecast of 39% and the 42% predicted by the contractors themselves."
Newcastle's local Journal tells us that NCG's contract in North East Yorkshire and the Humber had a success rate of 7.4% - but they're going to get a bonus anyway.
Okay, I must have missed the bit about bonuses when these contracts came out.  Perhaps they were negotiated at the same time as the "attachment fees" which meant that the providers would have a steady income and wouldn't be dependent on PbR.  But they are certainly a comfort to A4e and the rest.