Former McLaren driver John Watson has labelled the turmoil at his old team as "truly depressing" and pointed the finger of blame at engine supplier Honda.
McLaren, the once-mighty British constructor, are facing up to another season of bitter disappointment after a dour campaign of pre-season testing in which they recorded the fewest miles of any team.
Their Honda engine has proven unreliable - Fernando Alonso and his new team-mate Stoffel Vandoorne suffered a number of breakdowns in eight days of testing - and it appears to be painfully slow, too.
McLaren have already upped the ante on their Japanese partners. Last week they said they were considering the options on their 10-year deal with Honda, while racing director Eric Boullier claimed McLaren would be winning again if they were powered by Mercedes.
"I don't think those observations are helpful but they are probably fairly accurate," Watson, a four-time race winner for McLaren, told Press Association Sport ahead of Formula One's season opener in Melbourne on Sunday.
"The thing I find totally perplexing is that a company which is the largest manufacturer of internal combustion engines in the world, and provided championship-winning engines for the likes of Nelson Piquet, Nigel Mansell, Ayrton Senna and Alain Prost, seems to be incapable of making an engine in Formula One in the second decade of the 21st century.
"It is not rocket science we are talking about - we are not trying to put people on to Uranus or Pluto - we are trying to make a Formula One power unit that is good enough to challenge Mercedes.
"There has not been any sense of refinement from Honda that I can say gives me hope that a team, which I was part of, could ever in the short term return to the position where they are able to challenge for the world championship. I am deeply saddened by that situation. It is truly depressing."
McLaren have endured a miserable time of it in recent years. They have not won a race since Jenson Button triumphed at the Brazilian Grand Prix in 2012 and finished a lowly sixth in last season's constructors' championship.
The Woking-based team are entering their third season in a 10-year deal with Honda.
"Partnerships are what make successful Formula One teams," Watson added. "Last year, Honda made some improvements but nothing that would make any difference to the real outcome of their overall position. What we have seen so far this year does not indicate that they have stepped up to the plate and addressed the issues.
"Contracts are bits of paper, and within those contracts there are break clauses for either partner. But Honda is investing significantly into Formula One. It is a commercial contract and it is in the interest of both parties to make that work."
Alonso, who has won 32 races in a career which yielded the last of his two titles more than a decade ago, is out of contract at the end of the season.
The 35-year-old Spaniard, who has a highest finish of fifth since his return to McLaren, has said he will take a decision on his future after the summer break.
"Fernando would have believed that joining McLaren in 2015 was going to be a year of learning and maybe getting the odd podium," Watson added.
"In 2016 he would have expected multiple podiums and maybe a victory, and in 2017 to be challenging for the championship. I would imagine there is now an element of disillusionment in his own mind."
Source: PA
