Lewis Hamilton's quick reminder as Jenson Button drops hint

Jenson Button has raised a new and potentially significant concern in the debate swirling around the future of Lewis Hamilton, pointing out that his team-mate has been working all year on the development of McLaren's 2013 car and continues to do so even as he apparently weighs up whether to make a move to Mercedes.

It brings issues of trust and the sharing of technical information during the latter part of the season into question even as McLaren try desperately to get their championship back on track in Monza this weekend.

"We go through the whole season working on next season's car and developing the car and making sure we fit in the car and all that sort of stuff," Button said when asked whether development work had already started on the 2013 car.

"And we obviously give ideas of what we would hope next year's car would have even if it's small things like buttons on the steering wheel and different positions and whatever.

"You don't just arrive in December and say 'right, let's got on with it'. You plan through the year for the new year. Unless [drivers] wear blinkers they have seen lots."

Button did add, though, that he thought it would prove irrelevant whether his team-mate stayed at McLaren, and that "moving to another team wouldn't hurt me as much as much as I think it would hurt him".

For his part, Hamilton chose a timely moment to remind any prospective employers of his raw speed, bouncing back from the disappointment of Belgium last weekend, where he crashed out on the opening lap before becoming embroiled in a Twitter controversy, to top the time sheets on a gorgeous day at Monza.

The 27 year-old edged Button by just 0.038 sec in a desperately tight afternoon session which saw the top eight drivers separated by less than 0.3 sec.

As much as McLaren would like to devote their energies to increasing that advantage ahead of what will be a crucial qualifying session this afternoon, it was Hamilton's future which was again the main talking point.

McLaren team principal Martin Whitmarsh, in his first interview since BBC pundit Eddie Jordan claimed on Wednesday that Hamilton had "already agreed terms" with Mercedes, tried his best to play down the furore - even taking a potshot at Jordan's reliability.

In a BBC interview with Jordan, Whitmarsh joked: "I think that any article that includes a sentence that begins 'Eddie Jordan understands' is automatically questionable." The remark may or may not make the final cut. Whitmarsh was less bullish in other interviews, conceding that while Hamilton's management - Simon Fuller's XIX Entertainment - had said "lots of positive things" to him regarding their client's desire to stay at McLaren, he had "learned over the years that until people... ink the paper, you don't get too excited".

Whitmarsh also made a rather pointed remark about only wanting a driver who was "100 per cent committed" to McLaren.

"We don't spend any time, energy, concentration on stuff like that. We just concentrate on doing our job," he said. "We'll see. It will get resolved, but I don't think it is as big an issue in this team as in the media room."

You can bet that it is. While the title race will briefly reclaim centre stage this weekend, with Hamilton and Button heading into qualifying 47 points and 63 points behind Ferrari's Fernando Alonso respectively, the subject of Hamilton's future will not be far from anyone's minds.