By Andrew Benson Motorsport editor at the Spanish GP

Montoya has criticised his team this season

The Colombian is moving to McLaren at the end of the season and believes Antonio Pizzonia or Marc Gene should be partnered with an experienced driver.

With team-mate Ralf Schumacher likely to leave, Montoya told BBC Sport: "I'd take one of the test drivers - Antonio or Marc - and someone else."

"They're both quick enough and you need someone who knows the car."

Jaguar's Mark Webber is the favourite to move to Williams in 2005, with McLaren's David Coulthard also in the frame.

Australian Webber is under contract to Jaguar for next season, but has a clause in his deal that allows him to leave if the team are lower than sixth in the constructors' championship by this year's British Grand Prix.

Jaguar are seventh going into Sunday's Spanish Grand Prix, which Webber starts from ninth on the grid.

Sources have told BBC Sport that he is keen to move to Williams, who rate him highly.

Coulthard drove for Williams from 1994-5 and is less favoured by the team. The 33-year-old Scot is believed to be more likely to move to Jaguar in place of Webber.

But Coulthard has in his favour that he is a proven Grand Prix winner with 10 years' experience.

Sauber driver Giancarlo Fisichella could also move to Williams if they wanted him, but sources say the team doubt his hunger and commitment.

Indy Racing League champion Scott Dixon tested for the team last month and is due for another run in the summer, but he is unlikely to win the Williams drive because of the level of risk he involves.

Williams need a driver who can be competitive immediately, and the New Zealander has driven only on oval tracks for the last three years so would have a massive amount to learn.

And Williams will also remember their experience with Italian Alex Zanardi, who they employed in 1999.