Around 4,000 workers at Belfast aerospace company Shorts are on strike for a second day after six hours of informal talks between management and unions failed to find a way out of the dispute.
The two sides are due to meet again at the Labour Relations Agency in Belfast on Sunday - the first day the unions told management they could sit down around the table again.
The company said it was willing to have further talks before then to examine whether they could make progress towards more detailed, substantive talks.
However, it admitted in a statement that it believed "it is going to be difficult to make progresses, given the current mandate of the trade union leadership".
Members of Amicus and the TGWU mounted the strike in a dispute over pay, conditions, and redundancies after complaining there had been a total breakdown in relations with management.
Shorts, part of the Canadian Bombardier group, accused pickets of intimidating behaviour against those still going in to the main east Belfast plant and its satellite sites - some 20 per cent of the work force.
A statement said there had been instances including "sexual harassment, damage to cars, verbal abuse and pickets taking photographs of the cars of employees who were working normally."
They said they " deplore" such action and said the unions had a clear responsibility to organise pickets but appeared to be ignoring that responsibility.
A statement said: "Many of the shop stewards are on the picket lines but are taking no action to prevent this unacceptable treatment of fellow employees and fellow trade unionists who are not involved in the dispute".