Up to 90 jobs are at risk, including apprentices taking part in the company operator training scheme.
The first wave of redundancies from depots around the country are expected later this month with all operated plant services set to be ditched in July.
Over a dozen apprentices in the Hewden training academy will also be affected, with many left holding just red cards.
Adrian Murphy, new chief operating officer at Hewden, has decided to ditch operated plant services from the core plant fleet offer as part of a move to cut costs at the group.
Murphy joined Hewden at the start of the year from a more general hire background having worked previously as chief operating officer at Speedy Services and managing director of Hilti.
He took over from Kevin Parkes, who launched Hewden’s core fleet next day delivery pledge, which involved beefing up the operated fleet business last year.
This included a target of recruiting up to 250 operators by the end of 2015.
The national hirer will continue to supply operators with its mobile crane fleet.
Jeff Schofield, Marketing Director at Hewden, said: “Like any successful business, Hewden is constantly reviewing ways to optimise its business and improve efficiency in an effort to remain competitive and determine where we can add the most value to customers.
“As part of this review we are at present consulting with our plant operators around a proposal to redefine our operated plant plan.
“At the same time we are continuing to grow the business with further additional recruits in key areas such as HGV drivers and crane operators plus field and telesales teams.
“As a business we have invested more than £100,000 in training ensuring each member of the team has a life trade or up skill.
“As part of the consultation process, we are therefore actively looking at ways to redeploy as many as possible into other areas of the business.”
A source told the Enquirer: “Rival hirers have started approaching contractors and rival Lynch has done a deal with Carillion in the Midlands.”
Earlier this month Hewden revealed it was investing £1m in a range of Miller breaker attachments, which will see more than 180 new breakers added to Hewden’s attachment portfolio for use with its range of excavators from 1 July.