Car won't start!

[Jansy]

It's a diesel Mercedes "A" Class 170 Elegance on a 52 plate. The engine starts but cuts out straight away, only battery light lights up on dashboard, no ignition light, etc. no headlamps, tail lights etc. We have tried heavy duty jump leads but it's still the same.
Does anyone have any ideas why it won't start? Any help will be greatly appreciated.

[AlBags]

Main power maxi fuse somewhere blown? (sometimes these are built into the cable)
Check maxis in Engine fuse container.
I'll take a look in a while to see what they have on A class.

[Jansy]

Thanks AlBags, the problem's driving (no pun intended) the other-half mad!

[Craftypig]

Fuel?

[AlBags]

http://www.aclassinfo.co.uk/mypage.14.htm
http://www.aclassinfo.co.uk/mypage.15.htm

[AlBags]

http://www.baby-benz.com/portal/phpbb/

[jake-the-peg]

Immobiliser?

[Jansy]

Thanks everyone for your replies. Hopefully, the problem will be fixed by the other-half over the weekend. Fingers crossed.