"In the next three races, you need to be there and you need to be on the podium in all three races," the 25-year-old Spaniard, champion in 2005 and 2006, said.

"If not, you start to lose too many points."  

Alonso, who moved from Renault to McLaren last winter, is locked in a four-way battle for the drivers' crown with his team-mate, British rookie Lewis Hamilton, 22, the current leader, and both Ferrari drivers, Brazilian Felipe Massa and Finn Kimi Raikkonen.

Hamilton has 30 points after reeling off four podium finishes to become the youngest leader of the championship in Formula One history, while Alonso is second, two points behind, with Massa on 27 and Raikkonen fourth on 22.

"At the moment we are four drivers fighting for everything, but if one has two or three bad results, then maybe it's a little bit too far in terms of championship points," added Alonso, who won on the streets of Monte Carlo last year.

"To beat the Ferraris these days is so difficult.
 
"They are showing a pace that we don't have in a race situation and it's very difficult to beat them.

"Once they have a mechanical problem, as Kimi had in Barcelona or Felipe in Australia in the qualifying, for us it's a big opportunity to gain points from them."

Glitz and glamour

Meanwhile, Hamilton was easily seduced by the glitz and glamour of Monaco on the eve of opening practice on the most famous of all street circuits run round the houses, hotels, casinos and restaurants of the Mediterranean principality.

One of his McLaren Mercedes-Benz team's major sponsors had given both the 22 year-old and teammate Alonso a set of white diamonds for their racing helmets, as well as rings and bracelets for themselves and their girlfriends.

"I'm all blinged up," said Hamilton.

"I've bling on my helmet. How cool is that?"

Focused

He added, however, that he understood the difference between the glamour of his job as a Grand Prix driver and the real professional task of racing for victory.

"I feel very comfortable, great coming into this weekend. The team have done a great job, so I feel very optimistic about the whole weekend," Hamilton said.

"I'm expecting it to go well. I just need to make sure I am focused.

"You need to be focused here more than any other track because you have no room for error," added the championship leader.

"So you need to be relaxed, enjoy the atmosphere, the whole experience, but there is also a job to do."