Reacting to the publication of Network Rail's preliminary financial results for the year 2004/5 Bob Crow, general secretary of the Rail, Maritime & Transport Union, said: "We are not surprised that there has been some improvement in punctuality since maintenance has been brought back in house.

"There would be further improvements and savings if rail renewals were also brought back. The cost explosion on rail renewals will only be contained when the work is taken back in house.

"We estimate that the taxpayer can save £4 billion over the next 10 years if this is done. On the bonuses paid to the Network Rail directors - it cannot be right that these employees should be paid 25 to 37 times the salary of the average member of the railway signalling staff."