Fernando Alonso and Jenson Button have expressed confidence in McLaren's new car, as the team look to move on from a miserable 2015 Formula One season.

Despite the presence of two world champions, described by Ron Dennis on Sunday as "the best driver line-up in the sport", McLaren collected just 27 points last year on their way to a ninth-placed finish in the constructors' standings.

However, optimism abounds following the unveiling of the MP4-31, which will be used in testing at Barcelona from Monday.

"I have to say the brand-new McLaren-Honda MP4-31 really looks the part," said Button.

"Moreover, having spent quite a bit of time at the McLaren Technology Centre recently, I can tell you that there's a huge amount of palpable positive energy there at the moment, despite the challenging yet steep learning curve we all travelled along in 2015.

"In fact, the immense amount of sheer hard work that has gone into the development of the MP4-31 over the winter makes me immensely proud, and consequently I go into the new season with even more motivation and belief.

"Despite the ups and downs we saw last year, there were steady improvements all year long, and that gives us confidence in the design direction we're taking. There are a lot of positives we can build on, and a strong platform to take forward."

Alonso added: "Last year the spotlight was very much on McLaren-Honda as we embarked on the first year of our renewed partnership. It was a tricky season for all of us, but we learned a lot.

"The aero package (on the MP4-31) shows fantastic attention to detail. The whole car is beautiful in fact – it's particularly nicely packaged from an aerodynamic point of view as I say – and I'm 100 percent ready for the challenge ahead."

Dennis, the executive chairman and CEO of the McLaren Technology Group, said: "As we embark on the second year of our renewed McLaren-Honda partnership, all of us remain united in our purpose. That purpose is to develop our team towards our shared ambition: to win.

"We'll make no predictions as to when those wins will come, but I can say without fear of contradiction that every member of our team has worked with truly relentless dedication over the past few months. The result is that MP4-31's developmental trajectory has been usefully steepened over the winter, and I'm consequently very proud of our team's efforts."