A321s struggle with performance for some reason - going South there are no obstacles as it is over sea. As has been mentioned already the 757 would have no issues with a full load and fuel - it could probably make Manchester, nominate Corfu as an alternate and still comfortably make it off 35!
I am guessing it was hot? I was there a couple of years ago when it was 38/28 temp/dp. The heat index was insane!