By Andrew Benson BBC Sport Online motorsport editor at Silverstone

Juan Pablo Montoya is in prime position to claim his first victory of the Formula One season in Sunday's British Grand Prix.

The Colombian snatched a surprise pole placing in the dying seconds of Saturday's qualifying session at Silverstone.

Ferrari had looked on course to head the grid either through Michael Schumacher or Rubens Barrichello, but the Williams star leapfrogged them with an inspired final effort.

His lap of one minute 18.998 seconds was 0.034 seconds ahead of Barrichello, with Schumacher third, a hundredth of a second behind his team-mate.

It was a trademark brilliant lap from Montoya, who is making a speciality of setting pole at the last minute.

"To be honest I don't know where that time came from," said Montoya, who has now been on pole for four races in a row.

He said that the size of his improvement on the last lap had caught him by surprise when he was watching the three sectors of the lap coming up on the screen in his cockpit.

"In sector two, I looked at time on the screen and I saw only the last numbers," he said. "I thought: 'Damn, it's only a tenth quicker.'

"I didn't notice the numbers in then middle. I thought it was only a bit quicker, but it turned out it was a second quicker."

Schumacher and Barrichello were both out at the same time as the Colombian - and Schumacher in particular set a very fast time in the first sector of the time.

But both men were slow in the middle sector of the lap and they could not make up the time.

Barrichello blamed traffic and Schumacher said that the team had not managed to set the car up properly.

"We didn't get the set-up completely right to do the last sectors," Schumacher said.

"The first sector was OK, but the car wasn't balanced in the last sector so I had a couple of moments."

Jaguar in trouble

It was a disastrous session for the Jaguar team, who had hoped that a heavily-revised car would move them up the grid.

But the new aerodynamic package introduced by the team appeared to make almost no difference.

Eddie Irvine was 19th fastest - 2.8 seconds off the pace, and with only the Minardi of Mark Webber and Jaguar team-mate Pedro de la Rosa behind him.

Jenson Button qualified 12th for Renault, five places behind team-mate Jarno Trulli, after an engine failure in his race car forced him into the spare.