Rail passengers on some of the country's busiest routes, including an airport service, were today warned to expect severe disruption because of a strike by workers over pay.

The 48-hour walkout from tomorrow will hit National Express East Anglia, which warned it would only be able to run a limited services on routes including Stansted airport to London as well as between the capital and Southend, Norwich and Colchester.

Members of the Rail Maritime and Transport union and Aslef are joining forces to take industrial action, with three further 48 hour strikes planned for next month.

Andrew Chivers, managing director of National Express East Anglia, said: "The unions' demands are totally unrealistic, especially in this current economic climate.

"We have offered salary increases above the rate of inflation, and remain available at any time for discussions to reach a sensible, affordable and fair agreement.

"Strike action is unnecessary, simply not the solution and I would like to apologise to our customers."

The company claimed that Aslef wanted a minimum pay increase of 2.5 per cent, a four day working week for all its members and a 4 per cent increase in the number of train drivers, but the union denied it made these demands.

Talks between the two sides failed to break the deadlock earlier this week, with the unions claiming there had been a breakdown in industrial relations.

An alternative timetable is being drawn up by the company, which warned passengers that services which will run during the strike will be extremely busy.