The final decision on whether or not to change the law requiring all dogs to be microchipped will not be made until Wednesday.
On Tuesday evening MPs debated the Local Government Law Reform Bill and several amendments which aim to change the law on the microchipping of dogs.
As of July 1 all newly registered dogs will need to be microchipped - a change introduced in 2003 as part of the Dog Control Amendment Bill.
National, United Future and the Greens all oppose the law in its current form, but the parties have not been able to agree on how the law should be changed, so none of the amendments appear to have enough support to get through.
The House did not get through the debate on Tuesday night, and will pick up the issue again late Wednesday afternoon.