STRIKING train conductors are getting set to hold a referendum to see if a long-running rail dispute should continue.

More than 600 staff at Arriva Trains Northern could take part in an official ballot, to be carried out by the Rail, Maritime and Transport Union.

If staff are not in favour of carrying on with the 11-month-old dispute, then union chiefs may have to instruct them to return to work.

Union sources said that early indications were that there was still a positive attitude towards continuing strike action.

Last week Euan Cameron, Arriva Trains managing director, called on the RMT to hold a secret ballot.

But the Evening Press can reveal that discussions for such a ballot were all already well under way before Mr Cameron pressed the union.

Executive committee members, in London, have been discussing when and where to hold a ballot.

Today conductors were back on the picket line in a 48-hour strike, which will see services slashed on Christmas Eve.

An RMT source said of the proposed ballot: "This will be a referendum ballot to see whether we want to carry on, if it has been approved by the executive committee.

"It will be a formal referendum, held in secret. It is time for the membership to have their say and it appears there are opinions both ways.

"There is still a lot of strength of feeling about the situation among the membership."

The Evening Press understands that any ballot would probably be held in mid-January, possibly around the 10th.

Union members who have broken the strike to return to work would be able to vote, to the fury of some of their colleagues.

About 180 conductors are set to work the Christmas period as the RMT takes action today, tomorrow and on New Year's Eve.

Conductors began strike action in January in a protest over pay and conditions given to drivers which, they claim, have not been offered to them.

The strike is currently the longest-running rail dispute in Britain since 1922.

An Arriva Trains Northern spokeswoman said the company did not feel it was appropriate to comment at this stage.

Updated: 11:20 Monday, December 23, 2002