Lee Johnston has split with his Jackson Racing squad just days before practice begins for the 2017 Isle of Man TT, prompting speculation he could be standing in for John McGuinness in the factory Honda team.

Johnston was due to ride for Jackson in the Supersport and Superbike class while campaigning his own BMW Superstocker but he has now left the squad. Jackson now have a Superbike and Supersport entry going spare after Josh Brookes stepped in to McGuinness’ boots on the middleweight bike.

Brookes is already running for Norton on the Superbike but there are riders like Cameron Donald who don’t have a seat this year. Johnston, meanwhile, would be a good fit to ride alongside Guy Martin for the TT as Honda will need someone to get in among the top five.

Jackson Racing issued this statement today:

“Jackson Racing have parted company with Lee and wish him all the best. This wasn't in the plan but that's racing.

“We had a positive test with Josh yesterday (Tuesday), the team worked well together and are now focusing on the Isle of Man TT. It's late in the day but we are talking to another rider and are hopeful we can have at least two Supersport machines on the grid.

“The Superbike will be prepared ready with the view that if the right rider comes along then we will run it.”