Unions and contract companies employing workers at Total SA's (TOT) 200,000-barrels-a-day Lindsey Oil Refinery in the U.K. Wednesday revisited a labor dispute which sparked nationwide strikes earlier this year.

The parties were meeting in Doncaster, northern England, Wednesday to discuss a labor deal reached in June after thousands of contract workers in the U.K.'s engineering construction industry walked out in sympathy over layoffs at the Lindsey plant.

"The purpose of reconvening...is to discuss the impasse on the site where that agreement has not yet been implemented," the GMB union said in a statement.

Total said it would attend the meeting as an observer but declined to comment further because the workers were employed by contract companies.

"We want all issues to be resolved in order to get the project back on track and completed as soon as possible," the company said in an emailed statement.

Employers agreed in June to reinstate the 647-strong workforce on a GBP200-million construction project to build a refinery unit at the Lindsey plant. But the GMB said the 35,000 hours of work promised by employers hasn't yet been made available to workers, leading to many layoffs.

Separately, the GMB Tuesday began polling its members in the engineering construction industry for strike action on pay and conditions.

The sites being balloted between Aug. 11 and Sept.1 are: BP PLC's (BP) Forties Pipeline System, Ineos PLC's Grangemouth Refinery in Scotland, Royal Dutch Shell PLC's (RDSB) Stanlow Refinery in England, RWE AG's (RWE.XE) Staythorpe and Aberthaw power stations in England and Wales, Chevron Corp.'s (CVX) Pembroke Refinery in Wales and the Sellafield nuclear site in England.

The Unite union, which also planned to poll its members at the sites, wasn't immediately available for comment.

Around 50,000 people are employed in the U.K.'s engineering construction industry, according to the Engineering Construction Industry Association, the employers' group.

-By Lananh Nguyen, Dow Jones Newswires; +44 (0)20-7842-9479; lananh.nguyen@dowjones.com