McLaren originally announced Montoya would sit out the remaining eight races but Dennis today scotched his hopes of an early NASCAR debut by placing him on stand-by to return.

“Juan Pablo is fully contracted through to the end of the year and if we so chose he will test and race again,” Dennis said at Magny-Cours today.

“He is a contracted McLaren driver and will stay that way until the end of his contract unless there is some other commercial arrangement.”

Asked directly whether Montoya could race again for McLaren this year, Dennis claimed it was “more than possible”.

Dennis also put a block on suggestions Montoya could make his NASCAR bow as early a next month.

The Colombian is keen for experience in the stock car series and a chance to race in the second-tier Busch Series was spoken of. However, Dennis said: “There’s a conflict of sponsors, advertising campaigns – a whole raft of reasons why that is not a practical proposition.”

In Montoya’s absence, McLaren rookies Gary Paffett and Lewis Hamilton had been given hope of a Formula One debut.

The team will not confirm de la Rosa as a permanent stand-in but Dennis today poured cold water on hopes of a young British driver joining the grid this season.

“It is highly unlikely,” he said. “Their programmes are well mapped and they didn’t include racing a grand prix car this season. It’s more likely Pedro will continue in the car.

“But we as a team decide how the drivers are utilised, they are all contracted to us. They are the highest paid employees of all of our racing teams but they are just that.”

Dennis also explained his decision to drop Montoya, arguing that his announcement of a NASCAR move few in the face of a verbal agreement the two men had.

The Englishman claims Montoya was keen to stay at McLaren – and in Formula One - for 2007 and agreed to advance his claims to the drive over the remainder of the season.

He said: “A few races ago we had a conversation which was based on his desire to continue with McLaren, his desire to stay in Formula One.

“We came to a very clear understanding that the best way to achieve that was to have the best results in the latter part of the season.

“I felt if he was focused on having the best end of season then it would be easier for me to take a decision to keep him in the team or he would get a better offer [elsewhere].

“The common objective was ‘let’s get the best out of the balance of the season’, but that object was somewhat changed when he decided he would race in NASCAR.

“Then our objectives became different. The appropriate course of action was to let the whole thing cool off, let him think about the circumstances.”