Button and Hamilton have two wins each heading into the British Grand Prix
British Grand Prix, Silverstone, 9-11 July
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Qualifying: Saturday from 1210 BST Race: Sunday from 1210 BST
By Sarah Holt
BBC Sport at Silverstone
The battle between McLaren team-mates Jenson Button and Lewis Hamilton could come to a head at this weekend's British Grand Prix, Damon Hill says.
Hamilton and Button are first and second in the championship with two wins each heading into the race.
"It's just been on simmer so far and it will start to boil over," said Hill, world champion in 1996.
"Between the two British drivers in possibly the best car you will have a very close and fascinating battle."
The friendly rivalry between Hamilton and Button was tested on the track at the Turkish Grand Prix when Button passed Hamilton for the lead just after Red Bull team-mates Mark Webber and Sebastian Vettel had disastrously taken each other out.
Hamilton managed to re-pass Button to clinch his first win of the season but had initially been confused about why the team had allowed Button to overtake when Hamilton had been told to save fuel.
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Hamilton leads Button by six points after leading him home to a second successive McLaren one-two in Canada and a two-three behind Red Bull's Sebastian Vettel last time out in Valencia.
Hill believes tensions between the two team-mates - and successive world champions - will only heighten as the championship fight intensifies.
"Jenson will not be letting Lewis get away with anything," Hill, who has been team-mates with Alain Prost, Ayrton Senna and David Coulthard in his time, added.
"Your closest most significant competitor is your team-mate and when you've got a team-mate as good as Jenson then it's not a foregone conclusion.
"I know Lewis has the mindset of a driver who sees the normal state of affairs as him being first, which is great, and that's what you'd expect but perhaps Jenson is a little bit more opportunistic and slightly more mature and realistic about things.
"This could be the start of the rest of the season [for the McLaren relationship].
"Traditionally Silverstone [is] smack in the middle of the summer, smack in the middle of the season, the preliminaries are over and from now on the clock is definitely ticking.
"There is only room for one guy."
McLaren have had their difficulties in the past when both their drivers were vying for the title, famously between Alain Prost and Ayrton Senna in the 1988 and 1989 seasons.
Most recently in 2007, Hamilton and Fernando Alonso's tumultuous relationship led to Alonso, who had arrived at McLaren as a double world champion, quitting the team while the pair lost the title by a single point to Ferrari's Kimi Raikkonen.
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Hill agrees it can be more harmful to a team's championship chances to hire two star drivers but is certain that McLaren will do all they can to continue to allow their two champions to race freely.
"From a tactical point of view it makes more sense to always have one guy in your team getting more points," Hill added.
"But there are rules about team orders and we want to see competition.
"The teams I drove for didn't want a pre-arranged situation and I don't think that McLaren want that.
"It's frustrating racing as a driver if you're competing against another team that has that set-up [team orders] as you are fighting a war on two fronts.
"It can be frustrating if it's not that way in another team who are fighting for the title but we're not in that situation yet. It might come to that at some point and then it gets interesting."
Button, Hamilton, Vettel and Webber all head to Silverstone with two wins apiece with Ferrari's Alonso the other winner from the first nine races.
Hill, who won the title 14 years ago for Williams, says it is too difficult to predict which of the main contenders will claim the title - and that is just one of the reasons he is looking forward to Sunday's British Grand Prix.
"I don't think it's possible to call the championship right now," Hill said. "Thankfully it's an open championship and that's what we want to see.
Hill says Sunday's race has the makings of a classic
"I'm really looking forward to this event at Silverstone - I think it will be better than it ever has been before."
Hill, who is president of the British Racing Drivers' Club, ran the rule over the revised Silverstone circuit on Monday by completing several laps in a road car.
The new configuration lengthens the track by 0.472 to 3.666 miles and a new complex of corners flow out of Abbey before the cars rejoin the previous circuit at Brooklands.
"The old circuit has been changing since 1948 and is in a constant state of evolution," said Hill. "And this circuit is going to offer some interesting new dimensions.
"Having just driven on it there are some lovely new corners and it will be interesting to see what the F1 drivers make of it.
"They'll love the new Abbey corner and at Farm there is some potential in the race for overtaking by an immediate braking area after a long, fast left-hander.
"There are a couple of exciting new places but the track has retained its high-speed nature and continues to evolve."
The new 'Arena' circuit successfully staged the British round of the MotoGP championship in June and the F1 drivers will get their first taste of the track in the opening practice session on Friday at 1000 BST.
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