STRIKING health workers are continuing to picket hospital gates today as a dispute over pay looks set to spread.

More than 130 medical secretaries are on strike at the 1,000-bed City of Sunderland Hospitals NHS Trust.

Now, union bosses say more than 50 medical secretaries at South Durham Health Care NHS Trust, which includes hospitals in Darlington, Bishop Auckland and Sedgefield, are to be balloted over possible industrial action. Another ballot is planned at South Tyneside General Hospital.

Medical secretaries say they earn thousands of pounds less than colleagues elsewhere.

The great majority of medical secretaries working in the North-East and North Yorkshire are on grade three, earning a maximum of £13,285.

Their union believes it is time to close the gap on hospitals in the South and Scotland, which pay higher grade four rates or their equivalent.

Liz Twist, regional head of health for the public services union Unison, said members were determined to win.

The Wearside secretaries are in their second week of action. Last week, they striked for three days and, this week, plan to stay out until Friday.

Ms Twist said no new offer was on the table but they were ready to negotiate.

A spokeswoman for the South Durham trust said: "We have been advised of the formal ballot. We would hope this would not result in strike action. However, if this did happen the trust would do everything in its power to minimise the impact on patient care."