They absolutely have wage rises covered in all the new contracts...

They absolutely have wage rises covered in all the new contracts they are writing, even the older ones have some degree of coverage,
One thing that has to be noted is that for a new company to come in an underbid is an extremely risky proposition, the incumbent always knows where the savings are, increasingly the bigger listed players only want to deal with the transperancy of other listed players.
By my reckoning mil must have built up a sizeable order book of over 600 million, surely some private player would see value here given the contract book, there are are no other companies around with that kind of book trading on a market cap of sub 15 million