obstruction

noun

the issue was the major obstruction to progress on the peace process:

obstacle, barrier, stumbling block, hurdle, bar, block, impediment, hindrance, snag, difficulty, catch, drawback, hitch, handicap, deterrent, curb, check, stop, balk, restriction;

blockage, stoppage, congestion, bottleneck, hold-up;

Medicine occlusion;

informal fly in the ointment;

British, informal spanner in the works;

North American, informal monkey wrench in the works;

dated cumber.

obstruction Oxford Dictionary of English