UNION leaders claimed London Underground was in “a state of chaos” today as commuters suffered fresh disruption because of signal problems and other delays.

The Rail Maritime and Transport union (RMT) said London mayor Boris Johnson was presiding over an “unprecedented crisis”, claiming that the Tube system was in “meltdown”.

London Underground (LU) said problems with brackets on District Line trains, which led to a number being withdrawn from service, had been resolved.

But commuters on the Victoria line suffered a second day of delays as southbound trains ground to a halt at the height of the morning rush-hour.

Passengers at Finsbury Park were urged to seek alternative routes as trains were stationary on platforms - only to experience more delays on Piccadilly line trains which were reduced to a crawl as they headed into central London.

Meanwhile, talks will be held later today between LU, the RMT and the Transport Salaried Staffs Association to avert more strikes in a row over 800 job cuts.