"One of the things we are finding is the ability to move contractors who are overseas workers who have finished working in one particular area to another area now seems to be being blocked," Parton said.
"It's just a waste of resource.
"If they can't work somewhere, they aren't allowed to shift anywhere and it doesn't make a lot of sense and it's not helpful."
Parton said it was not necessarily a widespread issue but even if some people were affected, there was an issue.
"And that is 10 or 20 workers we can use somewhere else productively.
"The contractors have paid significant amounts of money to get them into the country and we need to use them to everyone best advantage."
Parton said the workers were needed for some time yet as maize and other crops were still to be harvested.
"A number of contractors have not had sufficient staff, they have been over worked, they have been stressed, they have worked probably longer hours to get the job done.
"I don't know of any serious accidents, hope there are none but that will be an outcome if we can't resolve this in the future."
Kevin White, who owns Bradfields contracting in Te Awamutu, said he needed an extra 10 workers for the maize season but officials would not let the workers already in the country move to a new employer.
"For example, we have someone in the Bay of Plenty and they are on a critical work visa, their job has run out where they are, they have applied for a job with us but to come to us they need to get a new work visa," he said.
"They can't come to us, even though they are an hour away and they will work for us."
White said it was just another unnecessary hurdle.
"It was hard to get people to get visas in short time spaces pre-Covid anyway, under Covid it's challenging, we have guys here whose visas are running out and they are struggling to get new ones," he said.
"It makes it just about impossible for them to move so it's a real challenge.
"It's hard enough to get staff in from overseas but it seems ridiculous when they are already here, why they can't move an hour away and carrying on working."
White said he had four other overseas workers that could come up from Southland as well.
An Immigration New Zealand spokesperson said the critical workers visa was restricted to the employer that applied for the visa on the worker's behalf.
They said anyone wishing to shift to a new employer needed to make an application to change their visa conditions, but generally that should not be a problem.
Immigration Minister Kris Faafoi and Agriculture Minister Damien O'Connor have been approached for comments.
- RNZ
