Last-ditch talks aimed at averting a strike by London bus workers over an Olympic bonus got under way today.
Thousands of members of Unite are due to walk out for 24 hours tomorrow over a claim for £500 for working during the Games.
Talks between union leaders and officials from bus companies are being held with the conciliation service Acas.
London Mayor Boris Johnson said yesterday that money is available for an Olympic bonus for London bus workers.
Mr Johnson told the London Assembly that £8.3 million was available from the Olympic Delivery Authority (ODA) for bus companies to compensate their drivers.
"It is up to the employers to get on and do the deal.
"There is ODA cash available to the tune of £8.3 million to compensate workers who are genuinely going to be doing more during the Olympics and Paralympics.
"In so far as they are going to be doing more, there is cash available from the ODA. It is absolutely vital that the bus companies now pull their fingers out and do this deal."
Unite official Peter Kavanagh said: "The Olympic Delivery Authority has made £8.3 million available for the bus workers. The mayor has instructed the bus companies to negotiate and we expect them to find the remaining money needed for a fair settlement.
"It is outrageous and irresponsible that the mayor and the bus operators have left it until the 11th hour to negotiate when we have been seeking an agreement for nine months.
"We cannot call the strike off until we are persuaded that TfL (Transport for London) and the bus companies are serious about resolving this dispute. With just hours left every minute counts.
"There are 20 bus operators. It's imperative there's a single forum to meet with the bus companies and TfL's involvement is vital in order to secure a deal."
An ODA spokesman said: "Games-time transport operations need to be robust and represent the best way of providing staff and services.
"The ODA has always undertaken to meet TfL's additional operational costs relating to the London 2012 Games.
"These costs are fully funded and will be met through our existing operational transport budget."