Motor racing chief Max Mosley has reminded Formula One drivers to race elsewhere if they are unwilling to pay for their super-licences.

The International Automobile Federation (FIA) president, replying to a statement issued by the Grand Prix Drivers' Association last week, said the fees demanded for the mandatory licences were reasonable.

In a letter to drivers copied to Formula One's commercial supremo Bernie Ecclestone, Mosley also offered an olive branch by assuring them any future rises would be limited to inflation.

The Monaco-based Grand Prix Drivers' Association (GPDA) has advised members to stall on signing their super-licences pending talks on what they consider to be unfair hikes in the fees demanded by the FIA from the start of last year.

The GPDA has also accused the FIA of using them as a revenue stream to fill holes in the budget.

McLaren's 24-year-old world champion Lewis Hamilton, who is not a GPDA member, will have to pay $270,000 for his licence under the points-based system. His earnings are estimated to be in the tens of millions, however.

"Apart from Formula One there are a large number of series and championships where a professional racing driver can earn a good, sometimes very good, living," Mosley wrote in the Feb. 11 letter seen by Reuters.

"The costs of such licences are fixed by the relevant ASN (national sporting authority) but are usually modest. A driver who does not want, or even cannot afford to pay for, a Formula One super-licence thus has many alternatives."