IF OLYMPICS transport arrangements sag during the next couple of weeks, stopping for a beer might be the best thing to do, according to the Mayor of London.

Boris Johnson was speaking as comparatively minor transport blips multiplied during the last few days of the Olympics countdown.

One of the latest problems affected Greater Anglia, whose operator Abellio apologised after yesterday's 30 C temperatures meant that some of its trains could not call at Stratford. Faults with elderly overhead lines installed 50 years ago are to blame, said Abellio, which explained that some of the wires were drooping in the heat. Network Rail has been replacing the OLE on the approaches to Liverpool Street in stages for some years, but the job is not yet complete.

Yesterday also saw delays on Southeastern's key Javelin services between St Pancras and Stratford International, caused by signalling problems.

These are not being seen as good omens for a transport system which must cope with almost unprecedented demand for two weeks once the Olympics open on Friday. There have been other difficulties over the past few days, including a suspension of Central Line services through central London on Monday evening, attributed to a track fault at St Paul's, just as volunteers who had attended a rehearsal of the Olympics opening ceremony were trying to get home. Their difficulties were made worse by parallel but unconnected problems on London Overground, which also serves Stratford.

The RMT union has called for an urgent inquiry into the wider implications of the problems. Its general secretary Bob Crow said: "While RMT fully agrees that safety must be paramount, we refuse to believe that this extraordinary move on a major route on the eve of the Olympics is not linked to the Government's systematic cuts to rail maintenance and renewal budgets and staffing.

“Hotter countries than Britain run trains without a problem and we have a right to know why key services are running on infrastructure that is half a century old with the inevitable consequences that we have seen."

The chief executive of the IOC has warned that London will need 'a bit of luck' to keep movng during the Games fortnight, citing the capital's narrow streets as another of the problems. He told the Financial Times: "We all cross our fingers. It’s not going to be easy."

Transport commissioner for London Peter Hendy pointed out that there's 'a huge amount of redundancy' in the London networks, and transport secretary Justine Greening said that although there could be problems at times, 'we got everyone home' after the Monday night rehearsal.

However, she is not claiming that nothing will go wrong. She conceded to the Guardian: "It is almost impossible to have the greatest show on Earth arrive in London and not to have some queues and some disruption, but the plans we have in place should hopefully minimise that down to the lowest possible level."

Mayor of London Boris Johnson, meanwhile, is staying philosophical. He said: “There may be times when people will experience delays, congestion. There may be moments when you’d be well advised to go and have a beer and wait for the situation to ease off a bit.”