The government is promising that jobs won't be on the line as a merger of the country's fire services into a unified organisation goes ahead - the biggest shakeup of the service in 70 years.

More than $300 million will be spent over the next four years merging the Fire Service, rural fire bodies, and volunteer fire brigades into a new organisation called Fire and Emergency New Zealand.

Minister of Internal Affairs Peter Dunne is at pains to say the restructuring isn't likely to result in job losses for firefighters, nor changes to their conditions of work

He says there may be some reorganisation of jobs, but it isn't a job cutting exercise, nor is it about changing conditions of service or employment.

"I think the feedback we've had and the fact that we've got everyone in the same room, everyone's supporting the change, indicates a sense of goodwill to making it happen," he sad.

Under the new scheme, vehicle owners will have to pay a levy to cover the cost of crash callouts, and homeowners will face slightly higher levies as well.

The $303 million package would be partly funded through a $161 million increase in the fire levy over three years, beginning in 2017-18.

Of the $161 million increase, around $30 million will come from broadening the fire levy to third party motor vehicle insurance.

At present, only those who take out house and contents insurance pay for the levy.