Wrangles have begun at City Hall over Bradford Council's attempts to introduce a new payroll system.

Union leaders have rejected any talks on managers' attempts to shift all staff to monthly pay.

At the moment, most are paid either weekly or four-weekly but the authority's new £160 million computer network has been designed to only issue monthly pay packets.

Earlier this week the two sides met to begin talks on bringing everyone on to the same system. But the public services union, Unison, has now rejected the approach, saying it is fundamentally opposed to any switch.

Unison's spokesman for Council staff, Patrick Kerry, said any shift would harm low-paid staff who budget their cash on a week-to-week basis.

"We are not entering talks on the move to monthly pay. The Council needs to have more flexible pay rules which aid recruitment and retention. We believe they should be operating a more flexible payment scheme and feel this is an attack on part-time workers," he said.

Unions have argued that the computer contract should have been negotiated on the basis that it could cope with the present three-tier pay system, and Mr Kerry said those concerns were expressed early on. "We said they were being optimistic and now we are being proved right."

In December, a document that went before the Council's ruling executive caused outrage by suggesting that the 15,500 staff not paid monthly could be dismissed and rehired on new contracts which included monthly pay.

But a Bradford Council spokesman said today: "Bradford Council has no plans to terminate and re-engage staff and is seeking a negotiated outcome."

Bradford Council signed the £160 million Bradford-i contract in July, ending months of negotiations between union leaders and management which saw the threat of strike action hang over the authority.

The authority said the ten-year partnership would mean better services for customers and make its own staff, payroll and account management more efficient.