Bob Crow, militant general secretary of the RMT transport union, warned that guards would walk out again next week and go ahead with a third stoppage on April 17 unless there was a breakthrough in the long-running dispute.
Up to 90% of services operated by nine of the network's 25 companies were stopped, despite management claims that they were able to maintain a few more trains than expected.
The striking guards claim the companies involved, including Virgin, Connex and ScotRail, plan to reduce their role to that of "Kit Kat sellers" by transferring important safety duties to drivers.
Mr Crow told BBC radio: "The underlying agenda of these train operating companies is to do away with the guards, save their wages and turn big profits into bigger profits for their shareholders."
Insisting the union was involved in a "class struggle", Mr Crow said greater responsibilities placed on train drivers were leading to more accidents and trains passing red lights without stopping.
"We believe in taking as much pressure off the train driver and allowing him or her to concentrate on driving the train and the guard can look after the passengers," said Mr Crow.
"If the driver is taken ill or incapacitated or involved in a collision, it is the guard who has the responsibility of putting certain safety devices down on the track to stop another train colliding with it."
Steve Bence, operations director of the Association of Train Operating Companies, hit back: "There is absolutely no underlying agenda to do away with guards. Bob Crow is simply not telling the truth." The association said there was little prospect of peace talks over the weekend, although it said RMT staff on Connex routes were talking with that company.
Operators plan to deploy more supervisors and managers to do the jobs of guards on Monday in an attempt to keep more services moving during the looming second strike.
Some of the biggest train companies, such as GNER and First Great Western, are not involved in the dispute after agreeing to write into their rule books a safety role for the guards.
Mr Bence said the industry's watchdog, Railway Safety, had agreed changes on the nine and denied that passengers were at risk.
"The rules were changed in 1999 so that the driver was responsible for dealing with the signalman in the event of an incident or accident, and the guard was responsible for looking after passengers," Mr Bence said.
"That is a sensible allocation of responsibility. For four years now the rules have been applied and been satisfactory. If the RMT want to change railway safety rules, they have to send a proposal to a company called Railway Safety, who as of yesterday are saying they have not received a proposal from the RMT."
Mr Crow is threatening further strikes into the spring in what is the biggest outbreak of industrial action since the signal workers' dispute during 1984-85 stopped trains over six months.
ATOC released figures recording the number of services stopped yesterday: Arriva Merseyside 50%, Connex 30%, Central Trains 90%, South Central 25%, ScotRail 50%, Silverlink 25%, Thames Trains 5%, Virgin West Coast 40%, and Virgin Cross Country more than 80%.
