First, selling only 40% of the shares in the companies is unlikely to make an difference to the way the SOEs are run. In particular the sell off will not make the firms anymore efficient since the government will still be the controlling shareholder.What I don't get is why Labour and the Greens haven't argued along these lines.
Second, if the government really does want to maximise the income it gets from the sales selling 49% is not a good idea. 51% is worth a lot more than 49%, that is people will pay a premium for control.
Third, selling to "Mums and Dads" will do nothing for the amount of money raised, since Mums and Dads will need a discount to make them buy shares.
Fourth, selling to "Mums and Dads" will do nothing for the efficiency effect of having private owners, since there will be too many "Mums and Dads" for them to be able to coordinate their effects to effect the firm's behaviour.
Fifth, given that each "Mum or Dad" will own only a very small share of any of the firms, they have little incentive to become informed on the firm's activities since they will only capture a very small amount of any improvement in performance they could bring about. This is another reason why performance is unlikely to change.
Sixth, the discipline of bankruptcy or takeover is not greater since the government is still the controlling shareholder and is unlikely to let either of these options happen.
These problems could be overcome by a well run competitive auction of 100% of the shares in the SOEs to all buyers, both national and international.