Thousands of commuters could be facing delays after a strike was announced by rail maintenance workers.
Rail services are under threat because workers at Balfour Beatty Rail Maintenance, which operates on the main line to London, have walked out in a long-running dispute over pay and conditions.
As yet, no-one has been able to confirm if workers in this area would be taking part in strike action.
The workers are members of the Rail Maritime and Transport Union (RMT) which is locked in a dispute over restructuring of pay and employment conditions.
David Bigg, chairman of Witham and Braintree Rail Users, said he was "very concerned" about the possible impact of the strike.
He said: "If the track isn't maintained then speed limits for trains will have to be reduced for safety reasons. This will inevitably delay commuters and will deter off-peak users altogether.
"Obviously the longer a strike goes on, the more chance there is of this happening. If the worst comes to the worst and a piece of rail breaks then services will halt altogether.
"But I hope Railtrack has contingency plans in place to make sure any maintenance needed is addressed as soon as possible."
Great Eastern Railway played down fears of rail delays: A spokesman said: "I expect there to be zero disruption. There have been strikes by rail maintenance workers before and there haven't been any problems.
"If a problem arises then Railtrack will simply contract out another rail maintenance company to make repairs."
GER added that as far as it was concerned, no maintenance workers would be taking part in the strike in its area.
An RMT spokesman said union members employed by Balfour Beatty Rail Maintenance walked out at midnight on Friday.
He said the strike would last until tomorrow morning because of a failure to reach an agreement.
Balfour Beatty, which operates in the Midlands and southern England, said it hoped the action would not affect services.
RMT members at another rail maintenance firm, GTRM, launched a week-long strike last Monday which the union said had hit services in the West Midlands and out of London Euston.
The union later accepted a deal with rail maintenance firm Jarvis to restructure pay and bonuses and reduce the working week.
Converted for the new archive on 19 November 2001. Some images and formatting may have been lost in the conversion.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article