Williams Deputy Team Principal Claire Williams says she would prefer less races. Photo: Sergei Grits/AP Photo

BUDAPEST Team chiefs in Formula One have warned against expanding the race calendar to 22 from next season, saying it will increase costs and the strain on staff.

"For me it's above all about the smaller teams and their workers," Beat Zehner, team manager of Alfa Romeo, said Friday ahead of the Hungarian Grand Prix. "With more races we would need more people."

Claire Williams, deputy team principal of Williams, said she "personally would prefer fewer races," fearing that an over supply could damage the spot.

In 2019 there are 21 races and increasing the number even by one in 2020 would lead to a record long season.

The Spanish Grand Prix, set to drop off, now looks like being saved having received backing from the Catalan government while the Netherlands and Vietnam have been added.

Germany's race looks in severe doubt and the future of Mexico is also uncertain.

More racing would call into question other activities such as testing before or during the season and how they would - or could - be done.

"It would have to be combined," Red Bull boss Christian Horner said.

There could also be an impact on the sporting rules given teams can only use a set number of engines per season before being penalized.

More engines for more races "would not make sense," Ferrari team principal Mattia Binotto said.