The figure for a voluntary budget cap in formula one next year has been increased by £10 million to £40 million.

Announced on Thursday, it was ratified by the World Motor Sport Council in Paris a day earlier, while at the same time the maximum number of teams was increased by 1 to 13 for 2010.

As the global recession bites, Formula One Management has also offered a US$10 million welcome payment for new teams, plus the promise of free chassis transportation and 20 air tickets for flyaway races.

Moreover, existing manufacturer-backed teams are being enticed to join the budget capping with the exclusion of engine costs. Marketing and driver costs will also not be included in the cap, the FIA confirmed in a statement.

An entry list for 2010, potentially featuring a full grid of 26 cars, will be published by the Paris body in June.

The big teams do not have to sign up for the cap, but their engines will be rev-limited, the test ban will continue to apply for them, and their cars will not be allowed to feature movable wings.

"The FIA believes that cost capping will prove attractive, and it hopes that over time all teams will join," the FIA said.

"So far, interest has been extraordinarily high from both existing teams and potential new entrants." Concerns have emerged that the new structure will form a two-tiered F1 grid, however.

Other changes to the 2010 rules include a bump up in the minimum driver and car package weight, making room for both larger drivers and KERS systems.

The move was apparently made in response to complaints that the sport is becoming a "jockey's competition" due to the addition of heavy KERS packages.

Most drivers endeavored to shed kilograms over the winter period, as they mused the addition of up to 40kg (88lb) in the form of the new energy re-use technology, but no corresponding increase in the minimum weight of 605kg (1,335lb).

The governing FIA on Thursday published the 2010 technical regulations, showing an increase in the weight from 605 to 620kg (1,335lb to 1,369lb).