Latest information on disruption can be found on the Network Rail website
Only local services south of Exeter are operating today. The operator First Great Western has confirmed that the disruption will last several days. A section of the track just north of Exeter was seriously damaged yesterday after it became totally submerged.
Plans to award a new franchise to run trains between London and the West Country have been put on hold while the government reviews the whole process.
A new contract was due to be awarded from next year, with First Group bidding to retain the franchise against three other rivals. It will now stay in charge pending the review, which follows the collapse of another deal to run the West Coast mainline
Staff from First Great Western are to vote on whether to strike in a row over bonus pay for working during the Olympics. Members of the Rail, Maritime and Transport union say the offer made to them was "inadequate".
They say other transport workers are being given bonuses worth hundreds of pounds during the games.