is the key code light going off as usual?
i agree with Alex, when you leave a car for a week it is not uncommon for it to get damp on the ignition components preventing it from firing up. a quick squirt or wd40 on each end of each HT lead (quirt the copper connectors) will often sort it out.
failing that you should remove a plug and check if it sparks when trying to start the car (while plug is connected to HT lead and touching engine for earth). no spark means you need to investigate why.
one possiblity that isnt uncommon in this situation is the earth strap. if the engine isnt used for a week the earth strap can remain damp for long enough to rust (especially at each end where it bolts on), and rust increases the resistance of the earth strap, preventing sufficient sparking at the plugs. try earthing the engine seperately using a good thick wire direct from the engine to the chassis, if it then starts you know the earth strap is the problem.
another thing to consider is battery drain. even a new battery can be drained over the course of a week, many cars constantly drain their battery, but this isnt a problem during normal use, however a week of drain can leave the battery with enough amps to turn the starter motor (often more slowly than usual) but not enough amps to turn the starter motor and fire the plugs. if the car bump or jump starts it would suggest this is the problem.
