A MOTHBALLED £250m refinery will start testing soon ahead of a possible return to production.

Germany's CropEnergies said it has decided to fire up the Ensus bioethanol plant at Wilton, Redcar, for a trial run that will start by July at the latest.

The troubled plant has been offline following a pause in production in February last year. Work was halted after bioethanol prices plummeted amid sluggish European markets and the lower oil price.

Since the temporary closure, numerous technical modifications have been carried out to improve its reliability and energy efficiency. These improvements, following their completion, need to be fully tested in a trial run, the firm said.

Last year, CropEnergies confirmed a quarter of its 100-strong Ensus team were leaving amid growing uncertainty about the site's future.

The factory uses wheat to create bioethanol, which is added to petrol.

The remaining protein and grain is used to make thousands of tonnes of animal feed and carbon dioxide for the soft drinks and food market every year.

But the site has endured a difficult history, with low demand, poor harvests, rising energy costs and even a bad smell forcing closures and hindering production since it started in 2010.

Labour MP for Redcar Anna Turley welcomed the trial restart and called on the Government to back the sector.

She said: “This trial run is positive progress towards restarting the plant after a long pause in production.

"However, CropEnergies are very clear that the UK needs to increase its commitment to renewal transport fuels to guarantee the long term future of the Wilton plant.

"We now need the Government to create the conditions to enable a full return to permanent operation and to secure jobs and future growth at the Ensus facility.”

In a trading update, the firm said: "It remains essential that EU Member States, in order to further decarbonise the transport sector, to meet renewable targets in both Member States and at a EU level and to protect local investments and jobs, continue to increase their renewable blending obligations. In particular in the UK, an early increase in the Renewable Transport Fuels Obligation (RTFO) and the introduction of higher ethanol blends are very important if the plant in Wilton is to operate on a permanent basis."

A further update is expected when CropEnergies' annual results are published on Wednesday.