A shambles. Sounds vulgar, but may not be; it may be a grouse shooting term. Customarily, shooters employ beaters to disturb birds on the ground and drive them into the air towards the guns. Normally one only shoots grouse hens, so if the beaters were by mistake to put up a grouse cock, they would warn the guns not to shoot by shouting "Don't shoot! It's a cock up!"
Can also be a transitive and intransitive verb.
One's whole shoot today was a disaster - one cock up after another. Now where's Camilla, the slapper? One feels like giving her a Dirty Sanchez. - Prince Charles
Another day, another cock-up - Tony Blair on the Iraq situation
The whole Iraq situation has cocked up badly - Tony Blair on the Iraq situation
I really cocked up Iraq, didn't I? - Tony Blair on the Iraq situation