The staff taking action are employed by a private company

The protest is part of a campaign for better pay and conditions for workers employed by a private company, Carillion.

Unions claim hospital staff taken on by the company are worse off than those employed directly by the NHS.

Members of Unison and Britain's general union, the GMB, are taking the one-day action after pay talks broke down.

The Northern Lincolnshire and Goole Hospitals NHS Trust says clinical services will be unaffected by the action.

And patients are being reassured their meals will be provided as usual.

More strikes planned

Unison has claimed that inexperienced staff were being drafted in from other parts of the country to cover striking workers.

But Carillion spokeswoman Paula Manning refuted allegations and said patient care was their "utmost priority".

She told BBC News Online: "All the people we are using as cover are experienced workers and well versed in patient care and health and safety requirements."

Carillion workers have already staged strikes on 10 and 11 April, and a further five-day stoppage is planned for May.

Speaking during the earlier walkout, Ms Manning said the company still hoped to find a "constructive outcome" to the dispute.