We made mistakes says McCully

National strategist Murray McCully concedes his party had some failures this year - it would be foolish not to, given it lost its lead over Labour and was lagging 20 points behind in the last Herald-DigiPoll survey.

But a concession is a concession: "You could say that our attack effort on some of the big debates perhaps didn't do enough for us relative to our needs."

And the meaning is clear: the party did not capitalise on large legislation-focused issues such as the Foreshore and Seabed Bill and amendments to the Employment Relations Act.

He acknowledged that leader Don Brash was less visible nationally in the second half of the year, focusing on regions he would not be able to visit in election year.

The difficulty for the party, he said, was that it made no sense to launch new initiatives when controversial laws that put the heat on Government were going through the House. However, that meant the party had "to invest heavily in those debates doing it for us".

"It is fair to say we probably could have done better out of some of them.

"The momentum probably needed to be better on one or two occasions this year."

Mr McCully is a controversial strategist in National, having been a close adviser to successive leaders from Jim Bolger onwards.

He has been widely blamed for Dr Brash's polling failures in recent months, and some are certain to see his admission over House failings as an attempt to divert the blame.

He would not discuss actual advice tendered - "advisers who are going to discuss the advice they give leaders should be fired" - but said that when things were not going well it was "a real test of character, for a caucus and particularly for those who are close to the decision-making process".

Mr McCully's formal title is parliamentary assistant to the leader. He is one of a handful of confidants who meet to thrash out issues of the day and advise Dr Brash: "There is a group of people of whom I am one who give advice and that's all it is; it can be accepted or rejected."

The others are chief of staff Richard Long, chief adviser Peter Keenan, party manager Steven Joyce, deputy leader Gerry Brownlee and chief whip Simon Power.

In Opposition, some of the judgments calls that were made were "reasonably marginal", he said.

A common criticism levelled at the advisers, mainly at Mr McCully, is that Dr Brash, the former Reserve Bank Governor for 14 years, is being moulded into just another politician. Mr McCully rejected that.

"A large part of his appeal as a politician is that he is not a conventional politician who lives in that world of trade-offs and compromise.

"Most of us are acutely conscious that we would serve him very poorly if we tried to suggest lines that made him no different from conventional politicians."

Several sources have insisted that Dr Brash's change in tune on the Civil Union Bill was a personal decision.

The changes to support the Cullen fund and four weeks' holiday pay were accepted by the caucus.

Mr McCully said criticism and blame went with the job.

"It is one of several risks I signed up to when I accepted the role I have. I didn't ask for the role. I was asked to do it and I knew what the risks were."

Asked if he was happy to continue in the role, he conveyed duty rather than enthusiasm.

"I think when people have had a significant investment made in them over a long period of time by their political party, that party and its leader are entitled to ask them to do difficult jobs sometimes."