How can I open my Xsasa estate boot?

Hi guys,

we recently bought a Y reg xsara estate, it has a boot that opens when you press a button on the remote control and also standard squeeze switch under lip on boot. I went shopping yesterday and when I got home I found I could not open the damn boot and had to get the shopping by collapsing the rear seats!!
It does not open via remote control or via the external handle.

Please help if you can,

Many thanks