Christchurch council held a key debate on local government reorganisation in private - due to legal advice.

Members of the public and press were told at the start of Tuesday night's full council meeting that the matter would be held under the line .

Members had been due to discuss the latest legal advice from outside counsel and decide on a way forward.

Leader, Cllr David Flagg, speaking just before those in the public gallery were asked to leave, said the item contained "exempt information." 

No information on the exclusion was given prior to the council meeting. The agenda still lists the discussion as public.

It is unclear as to when the decision was made and who took it.  

It is the second time the public and press have been excluded from Christchurch council during a key milestone of local government reorganisation. 

In December, the council barred the press and public from Christchurch's referendum count.