Talks between Toro Rosso and Honda have reportedly broken down, resulting in no deal being struck between the Italian outfit and and Japanese engine supplier.
The two parties had been discussing plans to create a partnership which would see Honda power the Red Bull sister team, replacing current supplier Renault.
With McLaren looking to divorce Honda following a turbulent three seasons together and Honda's deal with Sauber coming to nothing, the engine manufacturer opened up talks with Toro Rosso to ensure its future in Formula 1 was guaranteed, should McLaren pull the plug.
With the STR deal breaking down according to reports, due to a disagreement over the financials of the deal and a lack of time to prepare, it leaves Honda in a precarious position.
However it's expected McLaren will stay put with Honda for 2018, as its only option was a move to Renault power as both Mercedes and Ferrari have rejected any such deal.
With Honda confident it can match or even surpass the performance of the Renault engine with its 'Spec 4' upgrade due later this season, it makes sense for the British team to continue the partnership, which also delivers upwards of $100 million in backing from Honda to McLaren's budget, whilst in contrast the team would have to pay Renault for a supply.
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