McLaren are reportedly poised to lose £20m in sponsorship money next year, with two brands ending their association with the team.
The Woking-based constructor lost title sponsor Vodafone at the end of the 2013 season and has been without a lead sponsor since then.
However, according to The Telegraph, banking company Santander and Johnnie Walker will walk away from the team after the current campaign.
It is thought that Johnnie Walker's investment is worth around £15m a year to McLaren, while Santander pays £5m per season.
McLaren are currently ninth in the constructors' championship.
