Industrial action on the railways threatened to spread yesterday when another group of workers prepared to vote on strike action.

Station and retail staff working for Arriva Trains Northern are to be balloted on a pay settlement over the next few days. The move could result in them striking alongside the company's guards.

The guards staged the second half of a 48-hour action by the Rail Maritime and Transport (RMT) union yesterday, in their protest about a disparity between their pay and that of drivers. Fewer than one in 10 Arriva trains ran, although bus services introduced several months ago to cover for a shortage of drivers were unaffected. Talks to avert a second 48-hour strike on 6 February will be held between the two sides next week.

On Thursday, three more operators were served with notice of strike ballots in separate disputes over pay. The drivers' union, Aslef, has also announced a spate of ballots.

Workers at Silverlink Trains, which runs services from the Midlands to London, the Docklands Light Railway in London, and train drivers on ScotRail are to vote on walkouts. They are to vote on 24-hour stoppages as part of a campaign to win parity with drivers in other regions, Aslef said yesterday.

Meanwhile, the next round of strikes will be held on South West Trains on Monday and Tuesday, when RMT members will walk out in a row over pay and disciplinary procedures.

A ballot of London Underground drivers, simultaneous to the DLR vote though over a separate pay dispute, would be launched against the two companies at the same time, causing huge disruption in the capital.