The ETM joint venture won a place on Yorkshire Water’s five-year framework in 2010.

But the Enquirer understands staff were called into an emergency meeting at Aecom’s offices late last week to be told about planned lay-offs.

ETM currently employs 100 people with 60% of jobs now under threat at all levels from project managers to general construction operatives.

Redundancies among Galliford Try staff could start from as early as December 16.

One source told the Enquirer: “It has come as quite a shock to everyone in terms of the large numbers of jobs going.

“Work is drying-up on the current AMP 5 spending round and there aren’t many other projects in the business to move people on to.”

A Galliford Try spokesman said: “ETM is currently very busy with its AMP5 capital programme for Yorkshire Water.

“However, the majority of this work including three major schemes in the Sheffield region completes at roughly the same time this winter after which our workload will be insufficient to maintain the size of our workforce of around 100 people.

“In view of this we have started consultation with the affected workforce and their elected representatives which, regrettably, we anticipate will result in the need for fewer Galliford Try roles within the joint venture for a period of time while the AMP6 workload increases.

“Every effort will be made to redeploy those affected to other parts of Galliford Try.

“Last July ETM was appointed by Yorkshire Water to continue as a contractor for its AMP6 framework which starts in 2015.”