Up to 200 ancillary staff at a Scottish hospital may walk out if managers fail to agree to incorporate bonus payments into basic wages.

Unison officials were set to hold talks with managers at Lanarkshire's Law Hospital trust over what staff claim are 'unachievable bonus payments' of 5 per cent on basic wages.

Unison branch secretary Betty Rush said the criteria for the bonus, based on the hospital's performance against contracts, standards of staff work and attendance, were too stringent.

'In the six years the agreement has been running, the maximum we have achieved has been 3 per cent. We want the bonus scrapped and incorporated into basic pay.' Staff would be likely to call for a ballot on industrial action if their demands were not met.

Trust chief executive Ian Ross said: 'We are trying to thrash out the details of how the bonus can be incorporated into their basic pay.'