Union bosses have raised more questions about Bradford Council's decision to negotiate with a technology supplier to take over and update its computer systems.

They say changes since negotiations began have cast doubt over how the company can achieve the savings it has promised.

Last week the Council announced IBM/IT Net was the preferred bidder for the contract which is worth £115 million over ten years.

Unison, the council staff union, sits on the Council's steering group and has access to much of the information being used to draw up the contract.

It said an original bid by the company relied on the loss of 350 jobs but the Council has denied this, saying only around 100 jobs will go, through natural wastage.

Union bosses are now questioning where the rest of the savings can be made if the number of redundancies has been reduced.

A spokesman said: "It was 350 job losses to start with but they are now saying its 100 - so where are rest of the savings? We have not been told.

"The bid requires savings through business process re-engineering - which is business restructuring.

"They also say backroom staff would lose their jobs because the new systems would be more effective, but the systems haven't been proven."

A spokesman for Bradford Council said: "We are disappointed by the alleged comments from Unison as they are premature and unhelpful at this stage of the process.

"We have involved the unions throughout the bidding process and a trade union representative sits on the project steering group.

"The Council does not wish to discuss any matters of potential commercial negotiation through the media and is surprised that Unison should consider that it is either sensible or appropriate to do so.

"However, we hope that Unison will now return to its previously stated commitment to work with the Council to achieve a successful outcome to the Bradford project."

The selection of IBM/ITNET as the preferred partner will now be followed by detailed work and discussions between the Council and the company before any final decision later this year.