Management and unions at the Rolls-Royce aerospace plant near Bristol are meeting today to try and thrash out a deal to avoid strike action.
Workers voted to strike last week over the sacking of an Amicus union official. Nearly two-thirds of the 88 workers who voted, backed strike action after the dismissal of convenor Jerry Hicks.
An employment tribunal has since found that Hicks had "probably been dismissed on trade union grounds". His case will go before a full hearing in the next six months.
Tony Pearce, Amicus regional officer, said: "We will look at the situation and will not rush into anything. There is a further meeting with the company in London and hopefully we will try to resolve it."
About 1,000 workers from the rest of the plant could also be balloted for industrial action.
A statement by Rolls-Royce said: "We are clearly disappointed in the result of the ballot of a number of our employees from the test site. We have not been informed of any plans for industrial action."