Shares of Scarborough-based Sirius Minerals plc, the firm behind the controversial $5 billion fertilizer mine in North Yorkshire, fell more than 50% on Tuesday after it said it will slow down the development of the mine and cancel a planned $500 million bond sale.

Sirius said it will now seek a “major strategic partner” for the project, which supports about 1,200 jobs.

The company said it would conduct a review in the next six months to seek funds required for the project.

The $500 million bond sale was required to unlock a $2.5 billion financing package for the project.

Sirius said the UK government declined to provide support to facilitate the financing of the project. 

“The Government has reviewed the case for the provision of the support requested to facilitate the financing of the project and has decided not to provide the support requested,” Sirius Minerals said in a statement. 

“The company believed this commitment would have enabled the company’s financing to be delivered as planned,” it added. 

Sirius CEO Chris Fraser said: “Due to the ongoing poor bond market conditions for an issuer like Sirius we have not been able to deliver our stage 2 financing plan. 

“As a result, we have taken the decision to reduce the rate of development across the project in order to preserve funding to allow more time to develop alternatives and preserve the significant amount of inherent value in this world-class project.  

“The company will now conduct a comprehensive strategic review over the next six months to assess and incorporate optimisations to the project development plan and to develop a different financing structure for the funds required. 

“This is the most prudent decision to give the company the time necessary to restructure its plans to move the project forward. 

“The process will incorporate feedback from prospective credit providers around the risks associated with construction and will include seeking a major strategic partner for the project.”