Petrol flap and central locking?

Right, I dont think there is a manual release on these.
Try giving the flap/body panel a thump with your hand while operating the remote locking, that's often enough to get it open if it is just sticky. Once open, give the locking pin a spray with Plus-Gas lubricant ( I dont like WD40, I find it frees things off at first then dries and makes them worse ).

If that doesn't work, just remove the inner liner on that side of the boot and you will see the actuator motor. Again, give the locking pin a spray with Plus-Gas it might just be sticky. If the motor has failed it is easy to remove/renew.

fred
December 2009

Sorry Fred I thought I had.

It's Vauxall Zafira W reg.

Steve
December 2009

check close around the petrol flap in the boot area your car might have a EMERGENCY release may be under the paneling

wirecutterman
December 2009

Might help if you bothered to tell us what car it is. Some have a manual release in the back.

fred
December 2009