The latest Herald Digipoll survey had Labour on 26.5 per cent and its support among men had dropped to 24 per cent.
Last week's 3 News Reid Research, Roy Morgan and Stuff-Ipsos polls also had Labour in the mid to high 20s despite the publicity from its election year Congress and new education policy.
He said Labour was making changes to its campaign strategy and would focus on a narrower range of topics and major policies.
"We will stick to the Labour knitting and make sure everybody hears the same stuff at the same time."
A number of MPs have apparently made policy on the hoof recently, including Nanaia Mahuta saying on Marae that Labour would make te Reo compulsory in schools, which is not Labour's position, and Trevor Mallard's proposal for the resurrection of the moa.
Asked for an example of the kind of topic Labour would not be talking about under the new strategy, Mr Cunliffe replied "cosmetics and other stuff" - that was a reference to policy announced by Trevor Mallard to ban the import of animal tested beauty products.
He said it remained Labour policy but when asked if that meant he was not going to talk about the policy Mr Cunliffe replied: "that's right, so I'm not going to answer your question".
Pushed further, he said Mallard had not done anything wrong because it was a collective decision to release the policy. "We're just changing the way we do things."
There has been speculation some in caucus were considering options to replace Mr Cunliffe including talk of putting David Parker in the position, although senior MPs moved to dampen down that speculation, saying it was seeded by opponents to create instability.
Mr Parker said he had no intention of standing for the job and put the speculation down to rumours prompted by the polling.
Mr Cunliffe said Labour had discussed ways to turn the polling around and was confident he had the support of caucus.
"Sometimes when adversity comes it pulls you together and that is what has happened with the Labour caucus. We are ready to run, we are moving to campaign mode and are out for the fight of our lives."
This morning MPs said they supported Mr Cunliffe and defended his decision to take the holiday. Some also tried to turn reports of criticism from inside Labour ranks back against Prime Minister John Key.
Damien O'Connor and Chris Hipkins said at least Mr Cunliffe had holidayed in New Zealand and taken a short break unlike Mr Key who went to Maui for 11 days.
Mr Cunliffe said he was confident an anonymous Labour insider who criticised his decision to take a ski-ing break in the Sunday Star Times was not an MP.
He believed he knew who the person was, but would not comment on whether he had confronted the person about the matter.
Other MPs also said they did not believe it was a current MP, despite a reference made to going to Labour's caucus meeting today.