Act yesterday aimed a blow at National leader Don Brash, criticising his poor showing in Parliament and claiming he had lost control of his caucus.
National declined to respond in kind to its potential coalition partner but it did deliver a mild public remonstration.
Privately it went a little further
and hinted the salvo - fired by former leader Richard Prebble in the weekly Act newsletter - did not have the support of leader Rodney Hide.
Act has been unafraid to criticise the National caucus, but has generally praised Dr Brash. It believes he is closely aligned with Act, but also fears that, because of this, he will cannibalise Act's vote.
Its strategy so far has been to remind its potential voters they need Act in a coalition government to keep Dr Brash on the right track.
Yesterday Mr Prebble criticised Dr Brash's absence from Parliament over the past two weeks and questioned his failure to support education spokesman Bill English's attacks on the Government.
He also raised questions about National strategist Murray McCully's three-week absence from the House.
"It appears Brash has lost control of his caucus. He is clearly not leading it."
Dr Brash downplayed the comments on television last night and did not return the Herald's call. Deputy leader Gerry Brownlee simply said the party was "very happy with the way we are operating".
Others in National suggested an Act rift and TV3 reported Mr Hide had described Mr Prebble's comments as "unhelpful".
