Jeremy Clarkson has joked that he is doing a "pilot Radio 2 breakfast show" after Chris Evans revealed he is making a "secret Top Gear film".
The DJ, who has been among the favourites to take over from Clarkson on the BBC show, said he will be filming a "Top Gear sequence" with an independent production company this week and will "see how it goes".
A few hours later Clarkson, James May and Richard Hammond appeared to poke fun at Evans on Twitter, as Clarkson wrote: "Next week, I'm doing a pilot Radio 2 breakfast show with an independent production company. We'll see how it goes."
May tweeted: "I'm working on a new TV idea, with an independent production company, called TFI Thursday. We'll see how it goes."
And Hammond tweeted: "Next week I'm doing a pilot of The Two Show on Fridays with an independent production company. We'll see how it goes"
Evans, who presents a breakfast show on BBC Radio 2 and is making a one-off return with TFI Friday this week, has previously ruled himself out of the Top Gear job.
But asked by presenter Tim Lovejoy on Channel 4's Sunday Brunch whether he had started to present Top Gear yet, Evans said: "Not started yet, but we are doing a secret Top Gear film on Tuesday."
Lovejoy replied "It's not so secret now", but Evans went on: "It still will be, because nobody knows where it's going to be but we're going to make one and see how it goes.
"We're making a Top Gear - we're doing a Top Gear sequence with an independent production company and we're going to see how it goes."
The future of the motoring series was thrown into the air earlier this year when Clarkson was suspended after assaulting producer Oisin Tymon.
It is still unclear what will happen to the show after it was reported co-presenters Richard Hammond and May have been offered deals in the region of £1 million a year to stay with the hit motoring show.
That deal, which would make the pair among the corporation's highest earners, is said to be part of a plan to include a different guest host on each show rather than directly replacing Clarkson.
All three men's contracts ran out earlier this year and the BBC refused to renew Clarkson's after his much-publicised attack.
Andy Wilman, Top Gear's former executive producer - and an old school friend of Clarkson - has left the show, which sparked rumours he was joining up with all three men to make an alternative programme, with Netflix and ITV among the broadcasters rumoured to be in the running to screen it.
When contacted about Evans' comments the BBC said they will not be commenting on "speculation".