Rail companies say they cannot promise services will run without delay tomorrow following the sudden icy weather.

Connex, which runs services throughout Sussex, said tonight's weather would determine whether there would be cancellations and delays.

The freezing temperatures caused chaos on the county's rail network yesterday as points and signals froze.

The Brighton line was open but subject to delays and other routes were shut completely.

Closed lines included Lewes to Wivelsfield, Uckfield to Oxted and Hastings to Tunbridge Wells.

The service south of Horsham was also severely affected by the weather.

Connex replaced some services with buses, but they were also subject to delays because of the atrocious conditions on the roads.

All lines were reopened by this afternoon but rail chiefs were unable to offer a reassurance they would stay that way.

A Connex spokesman said: "The services are going to depend on the overnight weather.

"At the end of the day we are in the hands of Railtrack and what they do with the points and signals."