Industry sources revealed that over the past 36 hours the government used Keith Hill, deputy chief whip and a former political officer of the RMT, to press South West Trains to impose a 7.6% pay offer to break the deadlock between the company and the union.
Mr Hill, once a transport minister, was deployed by Downing Street as a go-between with the train operator amid rising government concern at a possible backlash from angry commuters.
The company had previously insisted that all industrial action, including strikes over the demotion of a union health and safety official, must be abandoned before the increase would be paid.
Stephen Byers, the beleaguered transport secretary, had earlier claimed that ministers would not intervene, but a senior industry figure said Mr Hill offered a "non-traceable" channel between Whitehall and SWT.
Sources at the Stagecoach-owned SWT confirmed yesterday that there had been official contact between the government and the company, but refused to divulge details.
Commuters on SWT routes in and out of London Waterloo face a third 48-hour stoppage on January 24 and 25 after a second walkout ended at midnight, again halting 80% of services on the country's busiest commuter routes.
Travellers in the north of England, including trans-Pennine and Merseyside services, also face chaos on January 24 and 25 as well as February 5 and 6 after the RMT stepped up their action on Arriva Trains Northern in a bid to win guards pay parity with drivers.
And in Scotland some one-in-four services continued to be cancelled as drivers staged an overtime ban over pay.
The attempt by the government to resolve the strike by the back door highlighted the problems it faces on the railway, with no sign of an end to a mounting industrial relations crisis on top of the deteriorating state of the network.
Mr Byers, who returned to work on Monday after a holiday in India, had earlier insisted that the government would not intervene.
"I am not prepared to go back to the days of 10 or 15 years ago when the government used to intervene directly in disputes of this nature," he said in a TV interview.
"It is for these parties to settle it and put the interests of the travelling public first."
The involvement of Mr Hill underlined the desperation of ministers to see a speedy end to the strikes as Mr Byers claimed he retained the full confidence of Tony Blair despite growing criticism of his performance as transport secretary.
"I speak to the prime minister on many occasions and I know that he's in full agreement with the action we've taken - as far as transport is concerned and in particular in relation to railways - and I'm hopeful that I will continue to maintain that confidence," Mr Byers told BBC radio.
SWT's decision to impose the 7.6% offer on guards and station staff and drop earlier "strings", including a demand that the union must accept a rise equal to inflation from October 2002, infuriated union leaders. Vernon Hince, the acting RMT general secretary, said it still fell short of a deal offered to drivers and failed to address the demotion of Greg Tucker, who coincidentally stood for the far-left Socialist Alliance against Mr Hill at the general election.
"I have never known such arrogance in all my years in the rail industry," Mr Hince said.
SWT's managing director, Andrew Haines, said: "The strikes have been a damaging and painful experience for our passengers, our employees and our company. It is vital we move forward and find a way to build trust between us."
