Refuse collectors in Ipswich have been offered a £1,000 bonus if they accept a controversial new four-day shift pattern starting next spring.

Negotiations between the Labour-controlled borough council and its bin collectors have been underway since it was first announced earlier this year that they would be changing the shift patterns from April.

However there has been no agreement with Unison, which represents the collectors, and now the borough has offered staff a £1,000 bonus – to be paid in April – if an agreement is signed soon.

The bonus would cost the council £42,400 which would come from its community and cultural services budget.

The changes will be introduced at the same time as the council brings in single status pay for all its staff – this is expected to mean refuse collectors earn less than they do at present, although council leader David Ellesmere has said that in the long term this should allow most members of staff to earn more.

The borough’s human resources committee is due to discuss the issue at its next meeting tomorrow evening, in a section of the committee from which members of the public and the press are excluded.

If the workers agree to the new shifts, they will work 37 hours a week – although the drivers of the lorries would work a further three hours overtime a week to complete a last trip to the disposal site.

They would work from 6am to 3.45pm Tuesday to Friday, with a 30-minute break for lunch to be taken before noon.

The borough’s Unison branch has written to the authority saying it still has many concerns about the proposed implementation of the four-day week proposal.

A key concern is the impact on health and safety of both staff and members of the public.

The letter from Unison branch secretary Suzanne Williams points out that during 2012/13 there were 15 fatalities nationally within the waste collection and recycling sector – three of them were members of the public.

It adds: “We struggle to see how the proposed compressed working our can have anything but a detrimental effect on the health and safety of employees.”

A reply from Gordon Mole, head of community and cultural services, says: “The health and safety of its workforce is IBC’s priority.

“The council accepts that it must continue work to minimise risk of harm to staff, as now, working in varied conditions.”