Both parties last night insisted that secrecy had been crucial as neither wanted to be seen to blink first in the highly-charged atmosphere of the first national firefighters' strikes for 25 years.
Union leaders and local authority employers, in a rare display of unity, agreed that the involvement of the conciliation service Acas offered the best - and perhaps only - prospect of a negotiated settlement before Christmas.
One well-informed labour movement source even suggested that ministers had been kept out of the loop to prevent government hardliners scuppering the initiative before it could be announced.
"The government has kicked the employers or the Fire Brigades Union, whoever moved first," the influential figure said. "A new process is needed." It is inconceivable, however, that ministers were not aware unofficially if not officially of a possible means to an end in the worst industrial crisis to hit the Blair government.
TUC officials disclosed that they were involved in discussions about the likely involvement of Acas last Friday, the day before the FBU general secretary Andy Gilchrist's controversial declaration that he wanted to replace "new Labour" with a more union-friendly "real Labour".
But few in the TUC's London headquarters were in any doubt that the resulting furore contributed to the union's decision yesterday to put its case to the conciliation service rather than strike for eight days from tomorrow or call further stoppages in the new year.
Mr Gilchrist's remarks had allowed the government to accuse the FBU leader of turning the strike into a political battle.
John Monks and Brendan Barber, the TUC's well-regarded general secretary and his heir apparent, discussed the proposal with the two sides after devoting weeks to their tortuous discussions over finding common ground and the way forward to let each side to claim some sort of victory.
Mr Barber, a fixer who excels in smoke-filled rooms and reputedly buys his shirts with the sleeves rolled up, has stayed in contact with the three points of the triangle involved in the dispute.
On good terms with deputy prime minister John Prescott and fire minister Nick Raynsford, he is close to Local Government Association chairman Sir Jeremy Beecham and the employers' chief negotiator Charles Nolda as well as Mr Gilchrist and his assistant Mike Fordham.
All the parties maintained that the initiative was taken by Acas chairwoman Rita Donaghy, a former TUC president and member of the low pay commission.
But others involved in the dispute suggested the Acas route was first floated by Mr Monks and Mr Barber after No 10 appeared to have tied the hands of fire authority leaders when it vetoed a draft peace deal that came within 90 minutes of averting an eight-day strike a week last Friday.
Mr Gilchrist said the involvement of a third party offered a "glimmer of hope" and warned the government that it would be making a grave mistake if it believed the union was in a weak position.
Ministers appear to believe they have the upper hand at the moment, scoring recent successes in the propaganda war including yesterday's publication of an official report arguing that the armed forces had coped well during the dispute.
Yet doves in the government acknowledge privately that it does not hold all the strongest cards, as other unions rally to the FBU's side and accuse ministers of seeking to starve firefighters back to work.
This week's Acas discussions are expected to lay the ground for detailed negotiations between the union and employers but the government is less a guiding hand and more a controlling fist. Any outcome will almost certainly depend on whether or not it makes public funds available in at least the short term.
A TUC source said he remained optimistic but Congress House was going ahead with plans for a national demonstration in London on Saturday in support of the firefighters.
