Those in charge of the future of the Olympic Park are increasingly pessimistic about the chances of being able to hold Rugby World Cup matches in the main stadium during 2015. A decision on whether to use the venue is required by the end of the month, so that officials can finalise their ticketing plans, but the logistics are understood to be proving extremely challenging.
While both sides are keen to use the venue, London Legacy Development Corporation (LLDC) executives believe that the cost of pausing construction work to the stadium to make it ready for West Ham United are likely to be prohibitive.
West Ham were selected as the preferred bidder for the main stadium tenancy in December and a LLDC board meeting on Tuesday will be asked to rubber-stamp the deal.
LLDC's chief executive, Dennis Hone, told the Guardian last week that he was "quietly confident" that the deal with the east London club, which involves spending £160m converting the stadium so it can be used by athletics and football, will be done. If, as expected, the board rubber-stamps the agreement then the Rugby World Cup plans will be at risk.
The sequencing of the work required is believed to be very challenging because cranes need to work on a new cantilevered roof at the same time as retractable seating is being installed, and the pitch is being ripped up to put in under-soil heating.
A range of options have been examined to try to find a solution, including the possibility of using the stadium without a roof for the Rugby World Cup. But despite their best efforts, senior City Hall figures now believe it is likely to prove too challenging because of the cost implications and the risk of embarrassment if the plan causes the work on the stadium to run behind schedule.
Insiders are keen to stress that they continue to work with Rugby World Cup executives to find a solution, but time is running out. The RWC 2015 chief executive, Debbie Jevans, toured the stadium last week and is willing to minimise the pause to construction as much as possible.
There is a desire to use the stadium due to its iconic status and large capacity, but if it proves impossible the matches would be redistributed around the country. An England Rugby World Cup spokeswoman said: "We are very keen to use the Olympic stadium as a venue if it is possible and practical to do so, and are in discussions with the LLDC."
As things stand, West Ham plan to move in time for the 2016-17 season. Having agreed to a demand from London's mayor, Boris Johnson, that a mechanism be found to protect the public purse if the club is later sold at a profit, West Ham will launch a wide-ranging consultation with fans.
British Athletics has confirmed that the London Diamond League meeting, due to take place in the stadium on 26 and 27 July, will be followed on 28 July by a meeting featuring the stars of London's Paralympics. The weekend of action will be called the London Anniversary Games. Major concerts will also take place in the stadium over the summer, before the conversion work begins in September.
