Fernando Alonso won the Drivers' Championship in 2005 and 2006

McLaren's Fernando Alonso says Honda is risking its reputation with its poor performance this year.

The Spaniard suffered an engine failure on his first lap in practice at the Spanish Grand Prix, the latest in a series of problems for Honda in 2017.

Alonso, who has half his $40m (£31.1m) salary paid by Honda, has had engine issues in three of four races.

"It is not my career, my ability, my image [at stake]. It is their career, ability, money and image," Alonso said.

"I try to support the team and drive as fast as I can, but the problem is not entirely mine. It is much bigger for them."

As well as Alonso's problems, team-mate Stoffel Vandoorne received a grid penalty at the last race in Russia because he had already used more engine parts than is allowed for an entire season.

Alonso, whose engine failed on his way to the grid in Russia, said that his problem on Friday was "in a way not a surprise", adding: "In Russia on Sunday we could not manage to complete the formation lap and here we would not complete the out lap."

He said he hoped that the engine would prove reliable in the race - the reverse of what has happened to him at previous grands prix this year.

A brief history of the Spanish Grand Prix

'If we can't compete, he will leave'

The problems are mounting for Honda as attention already begins to focus on the driver market for next year.

Alonso is out of contract at the end of this season and has said he wants to stay in F1 if he can find a car that will allow him to fight at the front. He says he will not take a decision until September or October.

McLaren executive director Zak Brown told BBC Sport: "If we can build him a competitive car, he will stay. If we cannot, he will leave."

The team are doing their best to persuade Alonso to re-sign and have put together a programme for him to compete in the Indianapolis 500 later this month.

The 35-year-old is flying straight to America after the Spanish Grand Prix on Sunday to start practice for the Indy 500 on Monday.

Honda's F1 engine is said to be about 120bhp behind the pace-setting Mercedes and Ferrari units, which produce close to 1000bhp, and there are widespread rumours that Mercedes are to assist Honda with their engine technology in an attempt to help the Japanese company catch up.

But Mercedes F1 boss Toto Wolff said: "We are not doing anything for Honda, that is the current status quo.

"So unless that situation changes, I don't want to contribute to rumours out there that are false and I think are damaging for Honda, and create hard standpoints from teams or other stakeholders. We will see what happens."