Union leaders have warned they could strike again next week

All lines were up and running on Thursday morning after the necessary checks were carried out by London Underground staff following the strike.

More than 2,000 Tube staff walked out on Monday in a dispute linked to the collapse of maintenance firm Metronet.

But the Rail, Maritime and Transport (RMT) union said another strike planned for Monday would still go ahead.

Assurances clarified

The strike was called off on Tuesday night but it took more than a day to get the network back to full capacity.

On Wednesday night passengers were still left struggling to make the journey home as the Circle Line remained closed and there were delays on the District, Metropolitan, Victoria and Hammersmith & City Lines.

Transport for London (TfL) said this was because essential checks on tracks, points and signalling equipment not done on Tuesday night had to be carried out across the network.

TfL said it had clarified assurances on jobs and pensions during nine hours of talks with the RMT on Tuesday to suspend the 72 hour strike.

The three days of strike action is on next week RMT general secretary Bob Crow

RMT general secretary Bob Crow said they now had the assurances, they had been seeking, in writing from the employer.

However, he warned a 72 hour strike planned for next Monday remained, pending the outcome of further talks.

"The three days of strike action is on next week," he told BBC News 24.

"Our view is the deal we have got is the best possible but if these people from Transport for London keep on going round and trying to rubbish us then it's their fault if the strike takes place next week again."