Health chiefs have been urged by unions to stump up extra pay for the hundreds of front-line staff who will be asked to work on the bank holiday that celebrates the Queen's Diamond Jubilee.

While many people will enjoy a long weekend of celebrations in June to mark the occasion, those in the NHS may be given a day off in lieu but will not automatically receive bank holiday rates.

Hospital trusts in Devon and Cornwall yesterday said no decision had been made about pay on the Diamond Jubilee.

But Unison and the GMB union, which represent health workers, said bosses should not wriggle out of paying proper bank holiday rates to those obliged to work on the day.

The GMB said the national agreement for bank holidays was to pay double time but some health bosses saw the holiday as an "extra" and were refusing to offer an enhanced rate.

Steve Pryle, from the GMB, said: "We had the same problem with the royal wedding when many health workers didn't get any extra money for working, they just got holiday in lieu.

"As a union, we have asked for them to be paid the enhanced rate if they are required to work."

Unison said a day off in lieu "wasn't enough" and the jubilee holiday should be treated the same as any other bank holiday.

Simon Newell, Unison's South West head of health, said: "This is meant to be a day of celebration and will be for most workers across the country, but it seems that it might end up being a second-class bank holiday for health workers in the South West.

"This problem stems from the Government who have declared this is a special bank holiday but have not provided additional funds to public services to enable them to continue to provide a service and pay those required to work what they are entitled to."

The late May bank holiday is being moved to Monday, June 4 with the extra jubilee holiday the next day.

A spokesman for the Royal Cornwall Hospitals Trust said it was currently in discussion with staff about the jubilee holiday – but no decision had been taken.

She added: "We are still discussing how we are going to manage the day. We haven't agreed anything with staff yet but are in the process of sorting it out."

The Royal Devon and Exeter NHS Foundation Trust said the issue was also being discussed by senior managers and "a decision was expected in the next couple of weeks".

The trust pointed out that it observed the royal wedding as a proper bank holiday and normal arrangements applied, with staff being paid at different rates above normal depending on their grade.

The South Western Ambulance Trust said staff required to work would be given a day off in return – just as they were during the royal wedding. But a spokesman said it was too early to clarify exactly what the rate of pay would be.