Britain hopes a provisional U.S. ruling imposing tariffs on Canadian aerospace manufacturer Bombardier (BBDb.TO) will not be politically influenced when new evidence is considered, UK Business Secretary Greg Clark said on Tuesday.

Clark said he was confident the British government could successfully fight the complaint, which was brought by Boeing (BA.N) and could cost jobs in the British province of Northern Ireland.

"Following the initial determination, there is then a further call for evidence ... we look to the U.S. to make sure that this is a rigorous process and is not politically influenced," Clark told lawmakers.

The U.S. Commerce Department has raised proposed trade duties on Bombardier CSeries jets to nearly 300 per cent, backing Boeing's complaint that the Canadian company received illegal subsidies and dumped the planes at "absurdly low" prices.

The decision could effectively halt sales of Bombardier's new plane to U.S. airlines by quadrupling the cost of the jets imported to the United States, although Clark said the jet did not directly compete with Boeing's aircraft.

Clark said British Prime Minister Theresa May had twice discussed the dispute with U.S. President Donald Trump, and that several members of the British government had reinforced their "serious concerns" with the U.S. administration over the ruling.

He added Britain would discuss the ruling with the United States, Canada and the two companies in the coming days.

Bombardier is the largest manufacturing employer in Northern Ireland, and the decision to impose duties on the planes has put 4,200 jobs at risk.

But Britain is also a major base for Boeing. The company has recently begun constructing its first European parts manufacturing site in Sheffield, northern England, and Britain has warned that Boeing might miss out on future business over the row.

"Boeing has a reputation in this country that was beginning to grow in a positive way, through the investment in Sheffield and elsewhere," Clark said.

"To jeopardize that reputation and relationship by doing something that is completely unjustified is something that I don't regard as being in the strategic interests of Boeing."