Forget about National sleepwalking to victory. The party seems to have gone into suspended animation.

National has gone so much off the boil in recent weeks that Labour smells a rather large rat.

Labour suspects its main rival is running a deliberate non-engagement strategy to protect National's most valuable asset - John Key.

Labour may well be right. National seemed to be using such tactics in Parliament this week as Michael Cullen, whose current good humour is an accurate barometer of Labour's surprisingly high morale, took on the role of Acting Prime Minister in Helen Clark's absence.

Cullen was spoiling for a fight. Key wasn't. Cullen is Labour's designated chief attack dog hunting down National's leader.

Key has everything to gain in trying to knock Clark off her perch. But he had little to gain in allowing Cullen to go head-to-head against him.

The upshot was Key did not ask a question in Parliament all week. Claiming Key had lost his bottle, Labour was also fizzing after National's leader unveiled a new policy forcing everyone convicted of a criminal offence to pay $50 into a fund compensating victims of crime.

Labour was not alone in seeing the decision to release the policy in Auckland as a sign of Key's gun shyness in the face of the Wellington political media following his widely publicised slip-up over National's Treaty policy and the fuzziness which surrounded National's stance on the sale of shares in Auckland Airport to foreign interests.

National always knew Labour would focus on Key's lack of political experience. What it did not predict was Labour's relentless highlighting of any and every inconsistency or hesitancy, no matter how small.

It did not expect a Labour fightback of extraordinary intensity; and Labour is only just getting started. National also never expected the Government to recover its equilibrium so completely. National, at times, has looked blinded in Labour's headlights and consequently paralysed.

National's script demanded Labour continue to play the lame-duck, arrogant, tiring, accident-prone Government it seemed to be modelling during the first two years of the current parliamentary term.

From National's perspective, things had looked fairly straightforward. When you are the main opposition party and registering voter support of around 50 per cent, it is a matter of sitting tight, being disciplined, holding your nerve and resisting pressure to start releasing detailed policy ahead of your own timetable.

All that has changed. The Labour fightback has seen National lose control of the political agenda which it was setting at the start of the year.