Momentum is building towards a deal to keep Fernando Alonso at Aston Martin beyond 2024.

The rumour built significant momentum across the Japanese GP weekend, as it became ever clearer that a move to Red Bull or Mercedes for the 42-year-old two-time champion was essentially off the cards.

Alonso said struggling Mercedes was "not attractive", while over at Red Bull, Sergio Perez seems to be heading towards a one-year contract extension.

"He is definitely having his best season with us so far," Dr Helmut Marko admits.

But also in the running is Yuki Tsunoda, with his surging current form at the junior team.

"I don't think so," answered former F1 driver Giedo van der Garde, when asked if Japanese 23-year-old Tsunoda really is in the running for Perez's seat.

"He's a Honda driver, so I think he will be taken to Aston Martin. Then Lance Stroll can go on holiday," he told the DRS De Race Show podcast.

Another former driver, Ralf Schumacher, agrees with that.

"He is primarily attractive for Honda, which is coming together with Aston Martin," he told Sky Deutschland. "As a Japanese driver, they will certainly have him on their radar if he keeps developing like this.

"I'm not entirely sure whether he's that interesting outside of Red Bull, but if he continues to perform like this, then yes."

One of Red Bull's top decision-makers Dr Helmut Marko, however, cannot help but to also consider whether the departing Ferrari driver Carlos Sainz might be an option.

"If the paddock radio is to be trusted," he told Speed Week, "Audi wants a decision from Carlos Sainz very soon. Aston Martin is also exerting pressure in several directions.

"We are not taking part in these games," Marko insists. "You will not hear from Red Bull about the next steps in terms of personnel until the middle of the season."

But according to Aston Martin, the Lawrence Stroll-owned team is more than happy with Alonso - whilst Lance Stroll's seat appears set in stone.

Pedro de la Rosa, Aston Martin brand ambassador and a close friend and long-time confidante of Alonso's, basically confirms that.

"The most important thing is to give Fernando reasons to stay with us," the former F1 driver told Cadena Ser.

"We desperately want him to stay with us," de la Rosa added. "And in the team we do not contemplate a different scenario. We are working for Fernando to continue and we are working as if he is going to continue.

"There is no plan B. Our plan A, B and C is Fernando. We are not looking around," said the Spaniard. "The team is very happy with Fernando and Lance.

"We brought some small improvements to Suzuka and we have a very interesting and very ambitious development program for the next races," de la Rosa added. "It is the most important weapon to convince Fernando - a car that is more and more competitive."