Sebastian Vettel refuses to deny he held talks with Mercedes

Vettel, who leads Lewis Hamilton in the title race by 13 points ahead of the Spanish Grand Prix, is in the final year of his three-season deal with Ferrari.

While Valtteri Bottas has impressed since he replaced defending champion Nico Rosberg at Mercedes - indeed he claimed the first victory of his career at the last round in Russia and is just 10 points adrift of Hamilton - the Finnish driver was offered only a one-year deal after he joined from Williams.

Reports have emerged from Italy that Vettel, 29, has already held discussions with Mercedes' non-executive chairman Niki Lauda to partner Hamilton next year.

When asked about the rumours that he could leave Ferrari to join the German manufacturer, which operates out of Brixworth and Brackley in Northamptonshire as well as Stuttgart, Vettel said: "The situation is clear and obviously the main focus is on this year.

"That is not a secret and it is not the line that I drop. It is a fact for all of us in the team that we find ourselves in a very good position this year.

"That is what we want to keep and want to use. Everything else is not that important."

Four-time champion Vettel won three races in his first season at Ferrari after quitting Red Bull. But, despite a strong start, he was warned last year by Ferrari team principal Maurizio Arrivabene that he would have to earn his next contract after a below-par campaign.

But the German has bounced back in fine fashion, winning two of the four rounds staged this season, and arrives here in Spain looking to build on his championship lead.

Fernando Alonso, who sat alongside Vettel in Thursday's press conference, dropped the biggest hint yet that he will not renew his deal with McLaren come the end of the season.

Alonso, yet to finish a race in 2017, is also out of contract at the end of the year, and said he will leave McLaren if they cannot prove they will be able to challenge for victories next season - a situation which appears unlikely given the British team's atrocious start to the new campaign.

"My intention or first priority is to race next year here, and not only to race, I want to win," said Alonso, 35. "I am happy with the team, but we are not winning.

"If from here to September or October we are in a position that I see clearly a possibility to win in 2018, I will be more than happy to stay with the team. If it is not the case then I will be more than happy to talk to anyone."