Belfast’s Bombardier plant could be at risk if the U.S. rules in Boeing’s favour in its preliminary decision on the dispute between the two companies next week, a Northern Ireland MP is warning.

“If this proceeds and there’s an adverse determination, that will cut at the competitiveness and the reality that we’ll be delivering the CSeries. If that is in play, then the Belfast plant is in jeopardy,” Gavin Robinson, MP of East Belfast, the riding where they city’s Bombardier aircraft plant resides, told BNN in an interview Thursday.

Bombardier’s Belfast plant currently employs 4,500 people and is Northern Ireland’s largest manufacturing employer.

“Bombardier plays a crucial role in our overall regional economy,” Robinson said.

Northern Ireland has been pushing British Prime Minister Theresa May to address Boeing’s claim that Bombardier is dumping the CSeries jet into the U.S. at “absurdly low” prices.

May raised the ongoing issue, and the importance of Bombardier to North Ireland’s economy, during a meeting with U.S. President Donald Trump Wednesday.