John,
There are 3 issues here.
EC261/2004 covers the airline carrier's responsibilities when there's a delay. It depends upon distance to fly, time of delay and geographic region (in or outside EC). let's assume the delay exceeds 5 hours - the carrier will need to provide meals and refreshments in keeping with the length of the delay. A voucher is a start but if your friends need more than £6 for a breakfast, pay the balance with cash and
keep the receipts. Without proof of spend they'l not be able to recover these costs from the airline.
They should also be provided with 2 free short phone calls.
If the delay takes the flight into the day following they should be put up in a hotel and transport provided between hotel and airport.
At the hotel, a meal and refreshments should be provided this evening. Alcohol is not covered by this but bottled water etc. definately is.
Some numbers - article 9 (1) (a) of EC261/2004 covers the meals and refreshments, 9 (2) the phone calls. 9 (1) (b) the hotel and (c) the transport between hotel/airport.
Your friends also have a right to cancel the flight and receive a full refund for the outbound flight cost - such to be paid within 7 days. They could then attempt to book an alternate flight. Article 8 (1) (a) covers this.
Your friends will also be able to claim against their tour operator - assuming they are on a package holiday and not a flight only. They should note the number of days they are delayed and recover that proportion from the tour operator. For example, a one day delay on a 14 night holiday - claim 1/14th of entire holiday cost back from the tour operator.
Your friends may also be elligible to claim from their travel insurance for delay in addition.
Your friends would be best advised to write a complaint letter (by hand) and present to the Excel rep at the departure airport before leaving. Get the rep. to sign a copy as having been received. Follow this up on your return with a cmplaint to the tour operator a.s.a.p. to ensure you meet their complaints procedure deadlines.
Any payment sent by airline/tour operator should be considered carefully. If you cash their cheque you forfeit the right to launch a legal case. So, if they are unhappy with any offer seek professional advice before cashing.
Finally, get them to contact Ros Fernihough on 01922 621114 upon their return.
Hope this helps them.