The French rugby federation has said the frozen pitch at the new Stade de France in Paris will be playable for England's opening Five Nations match on Saturday, but they warned it would be up to the match referee to make the final decision.

"As far as we're concerned the hot-air blowers are functioning and we are confident they will work," said Michel Renouleaud, the federation's spokesman. "Federation officials will be at the stadium regularly, but we have no plans for an official inspection."

A cover was unrolled over the pitch - parts of which are frozen to a depth of three inches - yesterday morning, and a battery of eight hot-air blowers are wafting a stream of air underneath day and night.

The weather forecast is for gradually rising temperatures in the region, although still hovering around freezing point.

The first test will come this morning when the cover will come off briefly for England's first training session at the impressive stadium, which will play host to nine of next summer's World Cup games.

"We will have a better idea then," Mr Renouleaud said. "But for the moment we are optimistic. We may go to the other extreme - the pitch may be muddy - but we believe it will be playable."