Eddie Jordan, a former team owner and now British television pundit, lit the touchpaper a couple of days ago by announcing he is sure McLaren's Hamilton is moving across to replace Schumacher at Mercedes.

"I know that his (Schumacher's) contract with Mercedes has a unilateral option for the years 2013 and 2014," the Irishman told German newspaper Welt, "so ultimately it's about whether he goes on or not.

"The only question for me is whether the decision has already been made or not. When I look at the available evidence, I think the change for Hamilton to Mercedes is very likely."

Jordan said he thinks Paul di Resta would be the man most likely to succeed Hamilton alongside Jenson Button, although he acknowledged that Kimi Raikkonen might be another option.

Force India's di Resta is keeping calm.

"It's all talk up and down the paddock," he told British Sky television, whilst giving nothing away.

The feeling in the paddock is that Hamilton's management XIX Entertainment is firmly responsible for the Mercedes rumours, but Hamilton on Thursday said he thought the saga was "not necessary" and destabilising for his McLaren colleagues.

"But what will be, will be," said the Briton. "It will all come out when it's done."

It is rumoured Bernie Ecclestone may - as ever - be playing a role in the subterfuge, and Hamilton did not even deny he has met with the F1 chief executive in recent days.

"He was telling me about getting married," the 2008 world champion joked.

So is Mercedes a real option for Hamilton, or just a lever to get what he wants from McLaren?

Asked if he knows who his teammate will be next year, Nico Rosberg answered simply: "No."

Team boss Ross Brawn is not ruling out Schumacher, insisting the seven time world champion still has "a huge amount of offer".

But is he talking about driving, or a new management role for the 43-year-old?

"With these technical changes we face, someone of Michael's experience and calibre would be a great asset," said Brawn.

In effect, he is not ruling out Schumacher or Hamilton as Rosberg's 2013 teammate.

"If we achieve what we want to achieve then we want to put ourselves in a position where every driver in formula one would consider driving for us," Brawn said.

He described Hamilton as an "excellent driver".

But is Mercedes a wise move for Hamilton, given the fact the German marque is yet to even sign a new Concorde Agreement for 2013?

Brawn said pen-to-paper on that matter is now "very close".

Button, however, advises Hamilton to stay at McLaren.

"I'd say congratulations to the guys at Mercedes for winning a grand prix this year but they haven't been in contention for a win as often as McLaren has won over the last three years," the former Brawn GP driver told F1.com.

And, anyway, if Schumacher has already decided to stay in 2013, there is no seat for Hamilton. Spain's Marca said a new one-year deal is certainly done.

The great German also revealed a new sponsorship deal on Thursday with a Chinese navigation technology company.

"You can approach the same topic from every different angle," Schumacher smiled, "but the answer will always be the same."

He has said repeatedly that he will decide by October.

But do the Hamilton-to-Mercedes stories change anything for Schumacher?

"I have heard them but I'm not going to say anything about it," said Schumacher. "I'm 43 years old, I am still competitive and still interesting for big brands," he is quoted by Germany's Focus.