'Cutting the fat out of Mfat' will be an easy political sales job for the National Government. Job cuts and radical restructures are normally anathema to voters.
In this case, despite Labour, NZ First and the Greens all rallying against the proposals, National should be able to convince the public that this is 'bureaucracy-busting'; bringing an archaic department into the modern age. The Ministry of Foreign Affairs and Trade is very much part of the Establishment in New Zealand, and therefore it has escaped much of the restructuring and downsizing that the rest of New Zealand society has endured over the last three decades. As Audrey Young puts it, it's been 'untouchable'. For the details of the proposed reforms see Derek Cheng's Ministry to lose fifth of staff in radical cuts.
The strongest critique of the Mfat proposals, so far, has come from a Kiwipolitico blog post, In an age of increased international interdependence, NZ shrinks diplomatically. This argues that 'market zealots of the National razor gang want to cut all perceived public sector fat regardless of consequence' - which will lead to New Zealand having less sway in an increasingly globally interdependent world, less ability to avoid 'military entanglements', and ultimately more costs as a result. Another potentially controversial aspect to the Mfat restructuring is the proposal to axe the Maori Policy Unit in the ministry - see: MFAT proposes scrapping Maori policy unit.
Not all commenters are opposed. Stephen Franks points out that this week's Economist magazine says that New Zealand has as many diplomats as India ('the world's second-most-populous country'). Tim Selwyn is also not a fan of the ministry and argues that the diplomats 'had it coming' - see: MFatigue. David Farrar also usefully canvasses the Mfat proposals in Restructuring the first deep cut.
Related to the Mfat changes, the leaked Murray McCully emails are still in the news - especially because of what they reveal about the Government's orientation to China - see Patrick Gower's Leaked emails 'not terribly embarrassing' - Key.