People who say there aren't enough open spaces in London obviously haven't visited ENO recently. Help populate this deserted wilderness and get 50% off tickets for "certain performances" of ENO's Medea in the process, using the Guardian Extra code GUARDEXMED.
I haven't been able to test this out because the ENO website won't accept my (compulsory) account details or send me instructions on how to reset them, but reader Richard says he was able to buy discounted stalls seats using the code.
I strongly suspect there will be further and better offers nearer to opening date. However past experience suggests these will probably be restricted to the upper levels. If you want to sit in the stalls, you might not get a better deal.