Toyota are poised to make a move for Jenson Button after it emerged that the new world champion was “disappointed” with Brawn GP's initial offer to stay with them.

Despite banking a multi-million pound bonus for winning the drivers' and constructors' titles, team owner Ross Brawn is keeping a tight rein on the purse strings.

While proper negotiations with Button over a new contract are set to take place after next week's final race in Abu Dhabi, it is understood his hopes of doubling or even trebling his £3million retainer have already been dashed.

That has alerted Toyota, one of the sport's richest teams, who are desperate for a top driver to give them their first victory after nine fruitless years in Formula One.

Toyota team president John Howett said: “There are a number of drivers around who people seem to think are fixed but who don't appear to be fixed. We're watching what happens in the driver market.”

Having clinched the drivers' title on Sunday, Button had hoped his loyalty to Brawn GP last winter would be recognised. When Brawn was struggling to keep the former Honda team alive after the Japanese car company quit the sport last December, Button took a massive pay cut from the £8m a year he had agreed with Honda to £3m.

Even if Brawn were to restore his wages to the Honda figure, Button would still lag behind Formula One's big earners — Lewis Hamilton, reported to be on up to £15m a season with bonuses at McLaren, and Fernando Alonso, who will get £20m at Ferrari next year.