So why has the night Tube launch been put on hold? And who cares?

London Underground still plans to go ahead with night Tube service (Martin Keene/PA)

No new dates have been confirmed yet, but LU is still keen to reach an agreement in time to launch the service at some point in autumn.

So what are the problems and priorities for all the groups involved, and what does everyone have to say about it?

LU employees have this month taken part in industrial action in protest against staffing plans for the night Tube service, and this week cancelled two more strikes at the last minute. Transport union RMT has already scheduled further strikes for September 8 and 10 if satisfactory agreements are not reached.

RMT general secretary Mick Cash said: "This move proves that our members were right to strike and were right to warn the public about the consequences of the mad rush to introduce the mayor's night Tube plans without agreement.

"The fact that the plans have now been suspended indefinitely to some vague date 'in the autumn' is clearly a massive embarrassment to both Boris Johnson and George Osborne, but gives us an opportunity to now get the basics that should have been sorted months ago worked out through direct negotiation.

General secretary for driver's union Aslef, Mick Whelan, added: "Aslef believes that a world-class capital city like London needs a 24-hour Tube service, but not at the expense of the work-life balance of our members.

"It has to be done in a way that works for London Underground, for passengers, and also for the drivers who deliver this service every day."

LU is confident that it will still be launching its extended service and reach fair agreements with unions within the next few months.

Nick Brown, managing director, said: "Further to the progress made in recent days with the trade unions and the suspension of strike action, we believe we are not far from an agreement that protects the work-life balance of our employees and is affordable, sustainable and fair."

London's Mayor Boris Johnson simply "isn't fussed" about the date of the launch, so long as it happens in the autumn, saying: "I'm not interested in a staring match over September 12."

He said he supported positive discussions with unions that would bring the start of the night Tube service closer, but that further strike action by LU employees "isn't going to benefit anyone."

Conservatives paint a fairly ominous picture of the future of the city's Tube service. London Assembly member Andrew Boff said: "The unions have won and Londoners have lost. The delay of the night Tube is a clear sign that transport unions are a barrier to progress. Their limitless self-interest has blocked something Londoners were clearly in favour of and put a halt to economic growth."

Liberal Democrats blame the mayor. Spokeswoman on the London Assembly Caroline Page said: "This is a big climb down for the mayor. His retreat is entirely due to his error in setting a specific start date before all the staffing arrangements and other issues had been settled."

Labour also hold the mayor responsible. London Assembly transport spokeswoman Val Shawcross said: "With Boris Johnson's blundering approach to launching the night Tube, sadly this delay comes as little surprise. If you try and launch a major project without speaking to the people you'll be relying on to deliver it, it's never going to end well."