Supply teachers could be heading for a small but welcome financial windfall - because of the royal wedding.

The extra bank holiday means the hourly rate for supply staff paid on national scales will go up by a few pence for the whole 201011 academic year.

The extra cash, largely in back pay, could stretch to a couple of rounds of drinks to celebrate Prince William and Kate Middleton’s big day.

A supply teacher at the bottom end of the scale, whose hourly pay is based on a full-time salary of #163;21,588, will earn an extra #163;43 based on a two-day week if they worked for the entire school year. A more qualified supply teacher, whose hourly rate is based on a full-time salary of #163;36,756, will get around #163;74 if they worked two days a week this year.

The extra day off for the wedding on 29 April means supply teachers must now be available to work 1,258.5 hours a year, rather than 1,265. So their hourly rate, which is calculated by dividing annual salary by the number of hours worked, will see a rise of a few pence.

However, these small payouts will not apply to teachers employed by outside agencies who do not conform to national pay and conditions arrangements.

Martin Freedman, head of pay and pensions at teaching union the ATL, said the cash would not amount to a great deal after tax and national insurance, but added: “This is good news for some supply teachers, but if all agency supply teachers were paid according to national pay frameworks they would all benefit.”

Unions have been battling for many years for equal pay and conditions for supply teachers, including the right to be including in the Teachers’ Pension Scheme.

Steve Tannian, payroll manager at Wolverhampton City Council, told Payroll World magazine: “This is an inconvenience. We’re currently waiting to find out how many supply teachers we have, then we can calculate the arrears payments.”