Competition for postal services will be introduced in April
"We are going to come up with some radical solutions," he said, promising to put forward a plan for the future within producing a plan for the way forward within the next three weeks.
"I think we have been too much inwardly focused, there has been too much infighting, and we have to get on and look at really focusing on our customers and competition," he said.
"Most of this is an attitude of mind, and therefore what you have got to do is clearly say everything is up for review," he said, acknowledging that this could include changing the name.
Last week Consignia said it had no intention of changing its name, after a press report said Mr Leighton thought it should go back to calling itself the Post Office.
Meltdown
Mr Leighton was interviewed on the Today program after a trade union warned that an inability by Consignia to cope with competition could cause chaos when the UK market for postal services is opened up next month.
The trade union Amicus had conducted a survey of 600 senior managers.
It found that two in three of the managers believed Consignia will not be able to cope, adding that almost all of them had complained about the company's leadership.
"The postal service as we know it faces meltdown if the current plan for competition is implemented too fast," said the general secretary of Amicus, Roger Lyons.
"Throwing Consignia in at the deep end will only result in the sharks picking off the choice morsels. The public will be left with an inferior service."
Unrealistic targets
Low morale, poor industrial relations and the increasing financial pressures facing the company pose serious threats to its future health, Amicus said.
The survey found that six in ten of the managers were suffering from stress caused by their work.
Two in three of them complained about being set unrealistic targets.
The union is seeking talks with Trade Secretary Patricia Hewitt and with Consignia bosses to discuss its findings.