Dennis signed Stefan Johansson from Ferrari for the season to partner Prost, but it was clear that the TAG engine was no longer competitive in the face of increased manufacturer involvement, and so Dennis approached Honda, who were at the time supplying rivals Williams and Lotus. Williams' unwillingness to accept a Japanese driver (Satoru Nakajima) in place of Nigel Mansell, as well as their displeasure with Williams team management for losing the 1986 Drivers' title, led Honda to transfer their engine supply to the McLaren team. Dennis made no secret that Johansson's seat was only temporary as his intention had been to sign the Brazilian Ayrton Senna (who had developed a close relationship with Honda while at Lotus in 1987) to partner double champion Prost. Senna was under contract with Lotus for 1987 but Dennis got his man and midway through the year it was announced that Senna would be joining the team, along with Honda, for three years from .