Olympic gold medalist says prologue win is 'a big ask' for Mark Cavendish

Boardman, who won his individual pursuit gold medal at the 1992 Barcelona Games, said the first two stages in Yorkshire would be real test.

He said stage one - from Leeds to Harrogate, through the Yorkshire Dales - will be tough, but he is hoping Cavendish will prevail.

"It's a lot tougher than people think it's going to be - possibly the Tour's toughest opening stage for decades," Boardman said at the start line in Leeds city centre.

"It does flatten off for the last 60 kilometres so that, if the sprinter teams really want it, they've got time to pull it back together which, of course, is what Mark Cavendish is going to want."

He said: "It is, as the footballers say, a big ask for Mark Cavendish. He historically takes a few days to get into his stride. He's up against it with Marcel Kittel, the new young German sprinter who's been on form this year as well.

"They've not met each other this year in competition.

"But Mark Cavendish must be aware of this career-unique opportunity for him, not only to take the stage win, which he's done before, but to do it in the UK and on the first stage which, of course, means that yellow jersey as the added bonus. So finger's crossed for him."

Chris Boardman had a long and successful career on the bike

Boardman, who rode in the Tour when it visited southern Britain in 1994, won the prologue three times, taking the yellow jersey on each occasion as a result.

He warned stage two on Sunday had a sting in its tail. He said Jenkin Road - a suburban Sheffield street close to Meadowhall Shopping Centre - would be an interesting challenge.

"It's a lumpy old day, all through the day," he said.

"But for me, Jenkin Road, with less than 5km to go, it's only 900m long, but it's steep.

"It will string out the peloton and it goes into a housing estate immediately, so there's a potential there for some small time gaps to develop."