In case sea freight hold-ups get to much, BMW has secured air options for post-Brexit part imports.

BMW has secured a contingency plan should post-Brexit customs checks hold up its production processes in the UK.

Britain's impending exit from the European Union is expected to cause delays at ports with increased customs checks, which could hamper the 'just in time' production method with imported parts being stuck in ports.

Mini Oxford plant

The German manufacturer has now confirmed that it has put measures in place to get round potential sea freight issues, namely  strengthening its air freight options.

"We have also taken measures to secure supply routes by air," BMW CEO Harald Krueger said on Wednesday

BMW currently produces most Mini products at its plant in Oxford and despite Brexit fears, it has confirmed that production will remain at the former British Leyland factory. About 60 percent of the 378,486 Minis produced by BMW Group last year were built in Oxford, but the components used were mostly imported from BMW's German factories.

Mini Oxford plant

BMW isn't the only manufacturer planning to swap sea freight for air freight in the event of a 'hard Brexit'. Aston Martin boss Andy Palmer has also confirmed that his company is also looking at the possibility of using air freight to bring in components.

"The European-sourced parts, which include the engine and the gearbox as a complete assembly, come back in from Europe so an alternative port is one way, predominately for lorries, and then reserving space on aircrafts for one-off shipping," Palmer told Reuters. "You can get a few days of engines and gearboxes relatively easily into the cargo decks of a plane so whilst it’s relatively expensive that is probably our primary backup."

Airports in Coventry and Birmingham, close to Aston Martin's Gaydon factory, have been touted as potential locations for the company's backup plan, while the port of Sunderland could accept Aston's imports in place of Dover should it decide to stick with bringing components in by sea.

Other foreign manufacturers with operations in the UK, Honda, Nissan, and Toyota, plus foreign-owned companies such as Bentley, Rolls-Royce, Jaguar Land Rover, and Vauxhall have yet to confirm whether they too will swap see freight for air freight after Brexit.

Gallery: BMW's Oxford plant set for electric Mini build