The company needed the prospect of a considerable drift back to work to give credibility to its threat to issue personal contracts to the 4,700 signal staff involved in the nine weeks of disruption.
But it admitted that 'very few' new union members had broken the strike. The Rail, Maritime and Transport Workers' Union said it knew of just five strikers who had gone back, fewer than on 15 June, the first day of the series of strikes.
Railtrack, which is to launch a pounds 100,000 advertising campaign in newspapers this weekend, said that it was considering 'all the options' to end the dispute, but a 48-hour strike on Monday and Tuesday is inevitable. A further one-day stoppage is planned for Monday week.
The advertisements, aimed at winning public support for the company's case, will stress the 'fairness' of its offer. Jimmy Knapp, general secretary of RMT, dismissed the adverts as a 'waste of money'.
About one-third of BR services ran yesterday, a roughly similar number to those on previous strike days. Signalling is being provided by about 250 managers, supervisors and non-union members and 250 RMT members not taking part in the strike.
Services to Dover, Brighton, Torquay, Paignton and Barnstaple ran for the first time yesterday but King's Cross was closed after being open during earlier stoppages.
BR said it hoped to run near-normal services today and tomorrow but there were likely to be delays early in the morning. Services will run down early tomorrow night. Every day is costing BR pounds 6m in lost revenue and the corporation is increasingly worried about the long-term damage to its business as travellers move to the roads.
Railtrack issued personal letters to signal staff but merely repeated details of its pay offer, which has not changed since 27 June. The company admits that many signal workers, who earn an average of about pounds 17,500 for a 50-hour week, would lose out by its proposals but says the majority would gain increases of up to 10 per cent.
Managers described the strikes on Friday, Monday and Tuesday as 'the most callous attack on the health of the railways, affecting work and leisure travel and cutting savagely into our investment reserves'.
David Armstrong, the company's director of human resources, emphasised his desire to negotiate with the unions until a settlement was reached but the RMT said there was little point in taking up his offer unless there was some sign of an improved settlement.
RMT leaders refused appeals to re-ballot the workforce. Mr Knapp said there was no need for a further vote as the strike was being solidly supported.
'The action that we are engaged in is quite within the framework of trade union law. Our members continue to demonstrate support for that, as they are doing this very minute,' he said.