British Grand Prix, Silverstone, 9-11 July Coverage: Live on BBC One, Red Button, BBC Sport website, Radio 5 live and mobile phones; text commentary each day online
Full details here Qualifying: Saturday from 1210 BST Race: Sunday from 1210 BST
Red Bull's Mark Webber has become the latest person to query the friendly relationship between McLaren duo Lewis Hamilton and Jenson Button.
The pair lead the standings going into British Grand Prix, but Webber agreed with Damon Hill's suggestion that the relationship could become strained.
"It's not easy having a fuzzy, warm relationship when [a team-mate] is a competitor," said the Australian.
"When you're at the front and trying to win there'll be a healthy rivalry."
Earlier this week, former world champion Hill said the rivalry between championship leader Hamilton and Button was "just on simmer so far and it will start to boil over."
Webber echoed those sentiments, based on his own experiences this season.
He and German team-mate Sebastian Vettel are fourth and third in the championships respectively, behind the McLaren duo, and they have had their own tensions.
The Red Bull pair collided at the Turkish Grand Prix when Vettel tried to overtake Webber to go into the lead, with the result being that Hamilton and Button came home first and second, with Webber third and Vettel failing to finish.
Team officials then became embroiled in a blame game over who was at fault, and although Webber said they were rivals, he said this came with the territory of running at the front of the field, and the incident had not caused any serious rift in the team or with Vettel.
"If Seb's drowning in the ocean I'd go in and help him out," he said.
"We don't hate each other's guts ... but it [the rivalry] is totally natural. You look at say [Lotus drivers] Jarno Trulli and Heikki Kovalainen, there's not much at stake so they are going to get on better."
McLaren have been keen to present a united front of friendship and harmony between reigning world champion Button and former champion Hamilton, staging photo opportunities of the two together. However, with the added pressure of their home race coming up, Webber said he felt sure "smoke and mirrors" were at work.
Red Bull team chief Christian Horner echoed his sentiments, and said he thought it would only take the slightest incident to cause tensions.
"Anybody who thinks Lewis and Jenson aren't competitive and won't push each other to the limit is sadly mistaken," he said.
Button and Hamilton joke about relationship
"They're competitive guys, they're the current and former world champions, and I don't think they [McLaren] have a number one or number two driver.
"I'm sure Jenson didn't sign a contract to be a number two driver there.
"It's inevitable in a competitive sport they will be pushing each other, and perhaps won't be having so much of a love in when that does happen.
"It will only take one small incident for things to flare up between the McLaren drivers, I'm sure."
McLaren have played down any talk of tensions between their drivers, and Button said he and Hamilton "almost wet themselves" with laughter when they read Webber's comments on Thursday.
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