Passengers face the threat of a total closure of the rail network after union leaders called for a ballot on the first national strike for more than a decade in protest at "creeping privatisation" .

Passengers face the threat of a total closure of the rail network after union leaders called for a ballot on the first national strike for more than a decade in protest at "creeping privatisation" .

The annual conference of the industry's biggest union voted unanimously yesterday to urge 18,000 workers at the infrastructure company Network Rail to walk out over a government plan to hive off part of the state-backed organisation's work to a private company.

Bob Crow, general secretary of the RMT union, told workers that the proposal to allow a private train operator to take over track and signalling on Merseyside was the "thin end of the wedge" .

Mr Crow told the annual meeting in Exeter that if the union acquiesced in the plan, ministers would give the same responsibilities to other private rail industries such as Scotrail, Great North Eastern Railways, Virgin and South West Trains.

The RMT leader said the expected decision to allow Merseyrail to take over the local infrastructure "beggared belief" and amounted to a "reprivatisation" . Mr Crow pointed out that last year Network Rail, which took over from the privatised Railtrack, took maintenance work back "in house" after the disasters at Hatfield and Potters Bar.

Transferring the work to Merseyrail, owned by Serto and Nedrail, a Dutch company, would have "serious consequences" affecting safety and the terms and conditions for RMT members, he said.

Mr Crow told delegates: "Merseyrail want to run signalling as well as train operations. Some people will argue it is only a small operator so it doesn't matter, but this will be the forerunner for the whole country.

"This is a guinea pig for train operating companies to run their own infrastructure. We want to send a clear signal that we will not sit back and allow this to happen without a fight."

He said it would lead to the same downward spiral which ended with the derailments at Hatfield and Potters Bar in which a total of 11 people were killed.

The last national rail action was taken by signallers in 1994. The entire system was virtually closed on strike days.

It is understood Network Rail is opposed to the plan for Merseyside, but is acting under orders from the Government.

A White Paper entitled The Future of Rail committed the infrastructure company to talk to any train operator seeking to take over the infrastructure in its region, where it was thought practicable. A parliamentary early day motion opposing the transfer of infrastructure to Merseyrail has been signed by more than 20 MPs.