P and O were certainly accepting cheques on Artemis on the cruise to Norway that ended on 6 June 2008.
The ticket for the cruise also says that you could settle the on board account with cash or travellers cheque.
P and O do however require a credit card to be registered at check in.
The quote I put in my question was COPIED DIRECTLY from P & O website. According to another questioner in these pages,they were told by P & O in Southampton (on 3 occassions)that they would not be able to use their maestro/switch nor cash and cheques.This led me to looking it up in their terms and conditions on the web and also in their 2009 brochure. It is possible that all new bookings are being told this change of policy and they are still allowing past bookings to use previously advertised policies.
There does seem to be a few differences between the P and O web site and what happens on the ship.
All the documentation, the ticket, the on board statement and its reference to personal cheques and the embarkation document, all say you can use alternative methods of payment including cash. I believe the welcome aboard pack said much the same
There is no qualification that this applies to some contracts and not to others.
Just found the P and O Southampton Disembarkation Arrangements document for 6 June 2008
It gives three option for payment
1 Credit card express checkout. Here they provide you with an interim and on day of C, a final statement. If happy the charge on your d=credit card is automatic.
2 Express cheque checkout. The same as credit card but you provide them with a cheque for th balance before 7.45 am on day of disembarkation.
3 Cash Payments "Passengers who have not registered any form of express payment and who wish to settle their account by cash or cheque should do so at the latest by 7.45am on Southampton morning".