Levels of future rail funding and train punctuality are due to be outlined in draft form by rail regulation chiefs.
They will propose just how much money rail infrastructure company Network Rail (NR) can receive for the five years beginning April 2009.
And they will also give an indication of how efficient they expect NR to be, what proposed rail schemes are affordable and what trains-on-time target NR should be meeting.
The "draft determinations" are being published by the Office of Rail Regulation (ORR), which earlier this year fined NR a record £14 million for engineering overruns at the new year that caused travel chaos.
NR has said that it needs £29.5 billion over the 2009-14 period, but it is likely that ORR will say that this figure is too high and that NR must make more savings.
In its rail White Paper last summer, the Government said it wanted punctuality to increase to a point where 92.6% of trains ran on time by 2014. The current figure is about 90% - the best for many years.
The White Paper also listed rail projects that were expected to go ahead in the period 2009-14. These included: the long-delayed £5.5 billion north-south, cross-London Thameslink scheme; a £425 million improvement at Reading station in Berkshire; and a Government contribution towards improvements at Birmingham New Street station.
The ORR is also due to comment on which schemes are affordable and will also give its views on the trains-on-time target.
The ORR is currently closely monitoring NR, particularly on its work on the West Coast Main Line where the worst of the new year overruns took place.
The ORR has agreed to NR's plan to finish the massive West Coast project by December. But this has meant NR is having to close parts of the line most weekends during the summer and the ORR has warned that disruption to passengers must be kept to a minimum.
